>I wouldn't mind those sites nearly as much if they let people pay with XMR.
This. I am subbed to anj0123's fanbox, but theres like half a dozen I would probably also sub to at least for a little bit if they accepted XMR or even some other coin, especially if it is possible to CPU mine it. I have a bunch of old computers and a few newer ones I use in the winter to either mine or do scientific research stuff with BOINC (I have electric heat so its effectively free since I would use that electricity anyway) and with all that I could probably sub to a few at least for a while.
Its not about the money for me mostly, I'm ok with paying a few bucks a month, its the privacy.
I also feel like there is a fine line or a balance to be found with paying for stuff in general. On one hand they definitely deserve to be paid, but on the other hand I feel like keeping stuff permanently locked behind a pay wall isn't great either. Like you said, permanence is one issue. At the same time, you cant just say that all stuff gets released after a set time period or nobody would pay, but instead just wait.