Because Belle's not funny or even all that rage-inducing. She's just an Onlyfans whore who panders to neckbeard interests and shows slightly more enthusiasm compared to most low effort e-whores. Her biggest controversy was when she sold bathwater. And even then, her fans were the bigger lolcows for spending hundreds of dollars on jars of water. Also, if she ever does anything interesting again, there's a porncow general for anything relating to porn/Onlyfans girls, so anything she does can be posted there and she doesn't need a thread unless she goes way off the rails.
Also, there are a number of similarly well-known e-celebs who don't have a thread yet. Asmongold doesn't have a thread yet, despite being 10x more controversial and famous. It took years for people like Hasan Piker and Mr. Beast to get threads, despite running into numerous controversies before then. The reality is that there's only about 20-30 posters on this site who have the autism needed to create detailed threads, 80% of whom exclusively focus on the Sektur and Nick Fuentes orbiters. Unless Belle starts riding the Memphis Micro or pegs Nick Fuentes, she's unlikely to grab the attention of the major thread creators long enough to get a thread.