One Piece relies too much on the luck factor, especially since the time-skip. The Straw Hats are a bunch of losers, but the circumstances always play in their favor. God Usopp was a disgrace. They can't defeat Sugar, then come the memes. Luffy can't defeat Cracker. No problem, he'll just eat his biscuit army. Haha, so damn funny. This kind of idiocy is what Oda loves. Here's another classic: Jinbe rescues Luffy and the others from captivity on Whole Cake Island, and Opera doesn't bother to mention it. What could he have done about it, anyway? Jinbe knocked him out. But the whole thing served to make them unprepared for the action against Big Mom. I won't even get into what happened during Wano, it would just waste more of my life. And yes, this has been happening continuously since then, and no change in narrative is going to fix this, no matter if Luffy became a Yonko or if the Straw Hats are called Yonko commanders. Not to mention that since the time-skip, it's almost only Luffy who gets fights, and he pulls off some serious asspulls there too.
As for Blackbeard... I think it will pretty much be a 1v1 situation between everyone, except for the Weak Trio, and it's likely that Robin/Franky/Brook won't be able to handle a fight completely alone, independently. And let's not even talk about Aokiji, the long-awaited betrayal will probably happen at the exact moment the Straw Hats set foot on Hachinosu.