i agree that he wasted too much panel time on throwaway characters like kidd and law that could've been used on the SHs, hell the last time sanji mentioned the all blue was when he sorta gave up on it at fishman island
Most readers expected post-TS to have each arc focus on a different SH getting a step closer to their dream, which in itself wasn't all that difficult to envision, wasn't a headcanon nor pure cope, either. We weren't saying, segregate Luffy away from those arcs, and let other SHs do the work. Luffy can still do his MC shtick, dunk the island villain, and win the day. But let
at least one other SH be important for the arc's resolution.
WCI was only a partial success. Punk Hazard and Wano shat on Chopper's medical competences. Robin only ever reads stuff in throwaway panels, without any actual plot importance during the current arc--would it have been so difficult to make a plot point she could've contributed to with arcane knowledge in either Zou or Wano? And now we've started the same shit all over again on the Island of the Future, where Futureman Franky does fuck-all tech-related, only appearing now and again to punch someone.
Horse. Shit. The. Whole. Of. It.