The political pressure (on crypto and banking) is also because of fraud. If you are transferring money via a blockchain with no KYC, it's going to be hard to get a legitimate banking partner to be happy with that.
Now when you say 'but it's only going to be used by the sex industry', you're adding another area of high fraud on top. It's hardly surprising that financial companies want nothing to do with two high-risk sectors sandwiched on top of each other.
Just look at Patreon and their continued stuggle with NSFW artists. I briefly worked on a similar smaller site that allows for artists drawing explicit things, and our payment processor would threaten us weekly to cut us off for arbitrary reasons. The chargeback/fraud rate did not differ based on the user drawing explicit content or not.
Now when you say 'but it's only going to be used by the sex industry', you're adding another area of high fraud on top. It's hardly surprising that financial companies want nothing to do with two high-risk sectors sandwiched on top of each other.