The problem for Zoro in Wano really is expectations
if you stop to remember Alabasta and Water 7 / Enies Lobby Zoro did almost the exact same thing, defeated fodders and the second strongest
But there was massive hype and hopes for Zoro to be great at Wano, the land of Swordsmen and Samurai
and in a way, Zoro did, he got a plotline with Yasuie and Hiyori
he got to show himself superior in battle above Hawkins, Apoo and Drake
he got a pretty great showing on the rooftop, unlocking CoC, scaring Kaido and blocking Hakai
and then he got to defeat the second strongest in Kaido's crew (like other arcs i mentioned) and unlocked Adv. CoC too
all pretty good stuff
but the problem is that Luffy outshines Zoro in the Post-TS way too much compared to the same arcs in the Pre-TS
yes Crocodile is stronger than Mr. 1, and yes Lucci is stronger than Kaku
but the difference never felt huge like Kaido and King
and it's not just Luffy, you also put Law, Kid and Yamato doing stuff comparable to Zoro and defeating Big Mom (the actual second strongest in the arc) and it feels like Zoro got shafted in Wano, because the expectations were on him, not on Law and Kid, and much less Yamato a new character that came out in at the halfway point of the arc
there's also the fact that Oda made all those setups for Zoro and it felt like he would have something else in the arc, forget ZKK, but the revenge Yasuie thing, Nidai and the Shimotsuki thing (i still have hopium that something can come out of this)
But yeah, if you take the expectations for Wano being a Zoro arc out, Zoro did pretty good this arc
a lot of good feats
great fights with great animation (I'm sure King's fight is gonna look great)
but it's hard to not expect more from Zoro in this island, and it also makes you not have that much hope for Zoro in the next arcs
because the next arcs have nothing to do with Zoro