I don't think having several villains is a problem in and of itself, I think it is just trickier to do well, and it is an added complication / wrinkle to try to work successfully into a narrative, and these movies tend to already be trying to tick so many boxes as it is. I think the obsession with backstories and (over)explaining every single thing about a character at the expense of a lean, mean runtime is much more of a problem than having a bunch of villains.
for superhero stuff i like when a movie can stand alone and is not bogged down by being part of broad comic book universes. i think chiefly it makes it hard to parse the stakes of the films conflicts within the context of a busy universe because often there seems to be problems with logically scaling those conflicts. also when should other characters show up and when should the titular hero fight his own battles? its just a mess imo that takes me out of it. like if superman or aquaman physically show up or even get mentioned in this batman movie i will likely lose my interest.
Yeah they’re not doing that again in 2022 as of now. Could change though of course if the Covid numbers keep going up.
I would also note that the WarnerDiscovery team probably has less deep pockets than Warner-under-AT&T, when it comes to make goods for the stars not getting box office backend.