While basically all of the CW superhero shows were either bad from the start or went downhill very fast after a season or two, honestly I have no complaints about the big crossover things.

Like... the individual shows got repetitive, boring, and formulaic, and the writers frequently had no farking clue how to tie even basic a- and b-plots together or progress storylines.

The crossovers, though?  The writers always lost even the illusion of having any farking clue what they were doing, often didn't even seem to talk to each other when writing their separate scenes, made a complete hash of character consistency and even basic object permanence (shiat like where a character was located) not just from episode to episode, but from scene to scene within an episode.  It was often incredibly apparent that the effects team had farked up, accidentally made something more awesome than the writers had asked for because they assumed they couldn't actually be being asked for something so stupid, and some extra lines were added in post to try to justify whatever special effects thing had just happened (and failing).  The episodes of the crossover were often aired literally across the series, aka at different goddamned times, so if you only watched some of them (like any sane person) you'd have to go back through youtube clips and find the other parts after seeing whichever you saw first and still have no idea what the actual fark.

They were a complete chaos of largely unconnected scenes that made no farking sense even within their own context, and somehow made less sense if you were familiar with any of the series and how they were supposed to connect to the crossover.

So, y'know, the most faithful adaptation of reading a comic book crossover event ever made, basically.  No notes.