Most of his movies I saw involve sex workers or are about some form of sex work. I wondered about the ethics of that and why he is so interested in this topic, but he is a great film maker honestly...
I don't know if ethics is the right word. Adrian Lyne did many movies about sex and infidelity after gaining prominence with Flashdance. He did Lolita, Fatal Attraction, Unfaithful, 9 and a half weeks, Indecent Proposal just to name a few. I think there might have been some other topics at well but he was known for examining movies of this genre of forbidden sex.
Like Scorcese with mob movies although his career has a wider breadth of topics.
Oliver Stone did a trilogy of movies on the Vietnam War that he served in.
Your art will tend to follow what you know best. Sean Baker is from New Jersey, and maybe he partook in the services of a NYC sex worker when he was younger or is just fascinated by that lifestyle. People on this board are fascinated by SPs and sex in film sells although maybe not as much as before with the prevalence of porn on the internet.
If there is one complaint I have about some of the reviews I have read or listened to on Anora, it is the idea that every sex worker is waiting for their knight in shining armor to marry them and rescue them from their life and they do sex work because they are struggling to make ends meet. This is such an outdated trope. There are SWs who are thriving and live a very adventurous and eclectic lifestyle.
Anyways, whatever his reason for delving so much into this genre of film, if the experience gained from past movies he made leads to a masterpiece, I am all for it. If it is just gratuitous crap then who cares. Sounds like he has done something special though with this film.