Like everything there’s some puritan morals involved. Most of which are around how sex and sexual desire are gross and not important. Couple that with the idea that suffering makes you a good person they all connect.
Also I think media plays a big role as well. Some toxic relationships are glorified in rom-coms and other media. Add in the normalization of weaponized jealousy in reality TV. Throw in the new micro cheating that the Internet and relationships experts who make mountains out of molehills. It’s a complex mix
I think independent social media like the Fediverse has uses with any group who would appreciate local control and free expression. I think the witchy community would fit that bill. I am unaware of any projects about it. At a certain point of users it would be inevitable just need someone connected enough to get it started.
Unrelated but I figured at a some point sex workers would flock here. Locally controlled by sex workers for sex workers would be a huge sell because they can’t be kicked off by arbitrary rules.