Well he hasn't given Zoro a real fight for the past decade either

I hope Wano will give him the same amount of growth Luffy had in the past couple of arcs; and that would mean at least 2 challenging fights. First he would fight an opponent around Doflamingo's level so he'd be forced to show his 'all out' power. Then against King he would get pushed beyond and get stronger with improved haki etc. I want Oda to finish off this arc with Zoro being around the same level as post WCI Luffy. Fighting Kaido afterwards is a different matter obviously and not as important as his individual fights