Zoro stopped being comparable to Luffy ever since awakening came into play. Luffy was superior even before awakening. The only thing that's debatable is the size of the gap.
Disagree, since the main advantage of Luffy's awakening vs Kaido was its blunt immunity. That's useless vs Zoro and any other swordsman for that matter.
G5's damage output is even lower than G4's which wasn't particularly high in the first place when compared to Zoro's lethality; in fact, G5's strongest attacks are only when its imitating G4's spring mechanism which tells us all we need to know about how the two compare to each other AP-wise.
Luffy is a mid top-tier feat-wise. He was also an excellent matchup vs Kaido as blunt immunity negated 90% of Kaido's moveset. Remove blunt immunity and Luffy's G5 performance vs Kaido is quite the same as his G4 performance, debatably worse.
Zoro was approaching top-tier as soon as he awakened ACoC. It wouldn't be hard for him to power creep to Old Garp level (which is
comparable to mid top-tiers), particularly as KOH gets less taxing for him which is the only thing holding him back from top-tier status.