All this is answered by what I’ve said- One Piece is ending soon. The only threats Luffy and Zoro need to face after Wano are the greatest threats they will ever see.
Shiryu, for example, is Blackbeard’s version of Rayleigh, Oden and Zoro. So the answer to the question of how strong he’ll be is very. It does not take much for Oda to hype up an opponents strength. We had no idea Oden was so powerful at the start of Wano. Two chapters ago the majority of readers here had Killer marked down as basically garbage.
Zoro doesn’t need to beat a YC anymore than Kid or Law needed to. He’s fighting Kaido and BM, that’s all the proof of strength we need.
But this all does not quite hold up.
Going back to Katakuri, you had a 1 vs 1 for Luffy to end on that level. Now you have a team fight required, but somehow you still scale each member of the team almost the same way in relation to the opponet as it was the case with just one guy fighting him in WCI.
Btw, how come Roger has multiple versions of Zoro ? Will Luffy end up worse off in terms of crew than him ?
And going back to Shiryu, why does Zoro need to be already stronger than him two arcs prior to even running into each other ?
Ok, so now in preparation for this fight Zoro did not need to prove himself. But after this fight he needs to be already proven for his EoS fight. You argue that he needs to prove that he's stronger than what comes next, and at the same time that he did not need to prove that he's stronger than a YC in preparation for him surpassing Oden.
So only Luffy needs to go through all these hoops and scale from YC 3 to YC 1 to top tier . Why not compare Zoro with a fellow SH, but characters that are not part of the crew and don't sail alongside Luffy ?
Here's how this could work out in my mind :
1. Fight at the top get's interrupted, and Zoro ends up fighting King. During this fight Zoro masters Enma, and when up against Kaido again he is ready to cut him.
2. Zoro rejoins the fight against Kaido, opens the old scar, and reminds Kaido of Oden. Such a monstrous Samurai was born again, he sees Zoro's potential to reach the same heights as Oden.
3. We get to the fight with Blackbeard, and Zoro is already stronger than all the other Yonko FM. He defeats Shiryu and in that fight he reaches Oden's level, and walks into the final war as a top tier.
4. Zoro defeats an Admiral, he has now surpassed Oden.
5. Zoro defeats Mihawk EoS.