This is a speculation that requires some amount of preamble.
I'll start with pointing out the somewhat superficial connection between Eustass Kid and this Lodestar. Lodestar comes from Lodestone. Lodestone was the natural MAGNETIC material used in early compasses for navigation and since they pointed towards the North where the Northstar was found, the Northstar also came to be known as the Lodestar.
Anyway the point is Lodestone is a magnet and Kid is the supposed Master of magnetism so to speak.
This is the connection that led me to this and so this is what I think has been going on with Kid for a while now.
Kid entered the Grandline two years ago and due to his powers, he doesn't really have to follow the usual log pose routes that everyone else does in order to traverse the grandline. Due to his magnetism he actually finds Lodestar via a shortcut of some kind without following the Yonkou ridden islands or those whacky islands everyone else kept running into like Raijin island or whatever.
Once on Loadstar, he found out that his proverbial princess was in another castle, that there is another island that can't be found by cheating using his magnetism powers.
Now he backtracked on his hunt for Poneglyphs and tried his luck with Big mom and managed to steal a rubbing of the Poneglyphs. Of course Big mom says only Luffy and Roger have pulled off stealing from her but she simply may not know Kid pulled this off if he has some very good stealth skills. Though maybe he was just spotted as he left and then got into a fight and fled and so the big mom pirates think they managed to chase him off before he accomplished his goal. Unfortunately he tried his hardest to translate the damn things and realised he doesn't have no Oharan or Kouzuki or Three eye tribe or Voice of all things and fails once again.
Notice the theme here is that Kid wants a Shortcut and keeps failing. First his magnetism gives him a shortcut to the finish line and it's not the finish line. Then he steals the poneglyph rubbings without actually engaging and defeating the Yonkou and he has no way of reading them. Of course Luffy tried this as well but failed as we saw and ended up in a very serious battle that's even continuing into this arc but Luffy will win this time and earn the poneglyphs he stole.
Next, Kid decides to do the thing everyone else has thought of but is too smart to attempt. He goes after a former member of the Roger pirates hoping to get another shortcut without having to struggle with reading the poneglyphs. Oh Lord why he chose Shanks and not Buggy or Rayleigh we shall never know but he does and he gets "disarmed" *badum tssss*.
Out of options now, Eustass Kid hears about some punks who have surprisingly done very well for each other by forming an alliance and defeating a big warlord. Kid's man Killer proposes alliances might be the way to go to actually get shit done in the new world against these monstrosities but once again, Kid takes a shortcut. Kid doesn't know that those punks who defeated that warlord did so by establishing a very strong emotional bond through their trials together and that is what cemented the strength of their alliance and kid doesn't have time for that. He believes just the single minded pursuit of his lofty ambitions is enough to just sway a certain magician and muscian to suddenly be fiercely loyal to this alliance and their goal. Lo and behold the muscian betrays the alliance and Kid gets smacked by a dragon and his man is mentally broken. Once again, shortcuts and failure.
That's brings us to now.
The only other thing left to discuss is what's next. Why is Kid having reached Lodestar and gone through all this important. Well like it or not, it's for Luffy's sake.
Luffy is the one who will be pirate king in the end and unfortunately everything in the story is leading up to that, including Kid as a character.
First of all, Luffy is the one who actually is on that shortcut that Kid wants. Roger reached Raftel through a life long journey spanning decades and Luffy is sprinting there in a matter of months. The difference between Kids' shortcut and Luffy's though is that Luffy works for it. He worked for his alliances to be as steady as they are, he worked for getting a poneglyph translator, he has been working for these poneglyphs. All the while Kid has been looking for the easiest work around all these.
The reason Kid and his journey are important is because Luffy will win him over by defeating Kaido and Big mom and Kid will give Luffy the shortcut to Lodestar. That's it. Kid has gone through all these failures so that when he sees Luffy succeed at basically everything he himself failed at, he will concede defeat and help Luffy by giving him a route to Lodestar no one without magnetism power can find.
P.s. Merry Christmas
I'll start with pointing out the somewhat superficial connection between Eustass Kid and this Lodestar. Lodestar comes from Lodestone. Lodestone was the natural MAGNETIC material used in early compasses for navigation and since they pointed towards the North where the Northstar was found, the Northstar also came to be known as the Lodestar.
Anyway the point is Lodestone is a magnet and Kid is the supposed Master of magnetism so to speak.
This is the connection that led me to this and so this is what I think has been going on with Kid for a while now.
Kid entered the Grandline two years ago and due to his powers, he doesn't really have to follow the usual log pose routes that everyone else does in order to traverse the grandline. Due to his magnetism he actually finds Lodestar via a shortcut of some kind without following the Yonkou ridden islands or those whacky islands everyone else kept running into like Raijin island or whatever.
Once on Loadstar, he found out that his proverbial princess was in another castle, that there is another island that can't be found by cheating using his magnetism powers.
Now he backtracked on his hunt for Poneglyphs and tried his luck with Big mom and managed to steal a rubbing of the Poneglyphs. Of course Big mom says only Luffy and Roger have pulled off stealing from her but she simply may not know Kid pulled this off if he has some very good stealth skills. Though maybe he was just spotted as he left and then got into a fight and fled and so the big mom pirates think they managed to chase him off before he accomplished his goal. Unfortunately he tried his hardest to translate the damn things and realised he doesn't have no Oharan or Kouzuki or Three eye tribe or Voice of all things and fails once again.
Notice the theme here is that Kid wants a Shortcut and keeps failing. First his magnetism gives him a shortcut to the finish line and it's not the finish line. Then he steals the poneglyph rubbings without actually engaging and defeating the Yonkou and he has no way of reading them. Of course Luffy tried this as well but failed as we saw and ended up in a very serious battle that's even continuing into this arc but Luffy will win this time and earn the poneglyphs he stole.
Next, Kid decides to do the thing everyone else has thought of but is too smart to attempt. He goes after a former member of the Roger pirates hoping to get another shortcut without having to struggle with reading the poneglyphs. Oh Lord why he chose Shanks and not Buggy or Rayleigh we shall never know but he does and he gets "disarmed" *badum tssss*.
Out of options now, Eustass Kid hears about some punks who have surprisingly done very well for each other by forming an alliance and defeating a big warlord. Kid's man Killer proposes alliances might be the way to go to actually get shit done in the new world against these monstrosities but once again, Kid takes a shortcut. Kid doesn't know that those punks who defeated that warlord did so by establishing a very strong emotional bond through their trials together and that is what cemented the strength of their alliance and kid doesn't have time for that. He believes just the single minded pursuit of his lofty ambitions is enough to just sway a certain magician and muscian to suddenly be fiercely loyal to this alliance and their goal. Lo and behold the muscian betrays the alliance and Kid gets smacked by a dragon and his man is mentally broken. Once again, shortcuts and failure.
That's brings us to now.
The only other thing left to discuss is what's next. Why is Kid having reached Lodestar and gone through all this important. Well like it or not, it's for Luffy's sake.
Luffy is the one who will be pirate king in the end and unfortunately everything in the story is leading up to that, including Kid as a character.
First of all, Luffy is the one who actually is on that shortcut that Kid wants. Roger reached Raftel through a life long journey spanning decades and Luffy is sprinting there in a matter of months. The difference between Kids' shortcut and Luffy's though is that Luffy works for it. He worked for his alliances to be as steady as they are, he worked for getting a poneglyph translator, he has been working for these poneglyphs. All the while Kid has been looking for the easiest work around all these.
The reason Kid and his journey are important is because Luffy will win him over by defeating Kaido and Big mom and Kid will give Luffy the shortcut to Lodestar. That's it. Kid has gone through all these failures so that when he sees Luffy succeed at basically everything he himself failed at, he will concede defeat and help Luffy by giving him a route to Lodestar no one without magnetism power can find.
P.s. Merry Christmas