Interesting that the 1930s, the decade that likely has the best claim to things genuinely being worse than in the past, is only bothering to whine about music being inferior... and they probably didn't even have recordings to compare the music to!
It's interesting that Megalopolis and Joker Folie A Deux are movies that kind of try to anticipate their own receptions in their stories, but with Megalopolis kind of delusionaly thinks it will win over the masses while Joker 2 pretty clearly knows that it will alienate them.
In fact I'm not sure there's much about these psyches to reveal. The psychological elements worked well enough in the first movie on what was basically a comic book level, but it's not interesting enough to be deconstructed over the course of a rather unrealistic trial.
Joker Folie A Deux is... actually kind of dull. I'll give it points for not being formulaic but the musical hook doesn't really work: the numbers aren't very entertaining in their own right and they don't really reveal that much about the characters' psyches.
The Joker movies are separate from the James Gunn/DC studios continuity like The Batman.