The Master was superior...
The Master, by Paul Thomas Anderson, was far better than Joker as a movie about mental illness... PTSD in that case (and perhaps more, even something similar to the stunted development in joker)...
It also starred Joaquin Pheonix, but his performance was better there.. instead of being a caricature, he seemed like a fleshed out man...
The movie also dealt with more interesting themes regarding "therapy", society's duty to the individual vs. self motivated improvement of one's affairs and wellbeing... As well as the cult stuff that was the setting of that movie...
I guess the comic book nature of Joker limits the movie significantly... it has to fit into the serialised nature of the comic book movie universe and the baggage of conforming to the idea of joker as either anarchist or incel-psycho...
Interesingly... Both movies illustrate the deep wound in modernity of what happens when the state or society replaces the role of the father (in both senses of the word)...
If you liked Joker, you might really enjoy The Master...