Over here (Belgium) we have legalized prostitution, but it's very hard for sex workers to open a bank account. There's some legislation that forces banks to offer them a basic bank account (at a steep fee) if they can prove that they've been rejected by N banks. Which is a start, I suppose.
Banks have basically become an extension of law enforcement, tax collectors, anti-terrorist operations, and morality police. Which is ironic, given how many banks brazenly break laws on the regular, how absolutely depraved parties with bankers are, etc. They're hardly paragons of virtue. Yet they get to gatekeep "virtue".
If legal, then why do banks have a problem offering an account. No risk of a bad actor, because it is legal.
It would be like a small business or contractor.