What you are allowed to host on your website is more about who hosts it and where its hosted. So you'd need to find a porn-friendly host to host your website, and then set up wordpress & plugins on that host once you have an account to begin building your website.
Then, like implied by
Count Morado above, depending of the payment processor you can use with this plug-in, you're fucked deep in the ass.
Most of them have clauses forbidding you to use their service for any kind of adult content. It pass for Patreon, and some other sites, because they have an agreement with the said payment processors. But as individual, you'll just be banned by this payment processor, loosing all the money possibly in the account at that time, and with no possibility to make them change their mind, nor possibilities to open another account other than, perhaps, opening another real life bank account.
Plus, not all those payment processors are available everywhere in the world, and as individual having to supports many different ones is one more burden on your shoulders.
And, finally, if you life in a more or less modern country, platform like Patreon generally take care of the taxes for you. Not that they pay it, but they do the math, and you know exactly what sums you've to declare.
In the end, Devs don't do it because devs aren't totally crazy.