>>83229980In the 80s/90s it became more and more popular to be skinny as a rail, leading to the "Heroin Chic" stuff. There was some blowback, and around that time Rap was getting popular which led to more images of big asses. Around the same time the internet was getting popular, and fat fetishism (always extremely niche and under the radar) sort of blew up.
So that's been going on for a while, and now a lot of the people old enough to live through that are less ashamed of their fetish. Plus there's a big thing with radfems for more "body positivity," which means more fat girls are being publicized, which is good for fetishists.