Someone asked this on Reddit yesterday, but apparently, it already got deleted. In short, from what I remember, OP asked why Hybe didn't take Somi and debut her in their girl group since she's so popular, and her star power is wasted by just being a soloist. She would bring a lot of benefits to the group, something in that line. Surprisingly, many kpop fans didn't know that Hybe didn't exist before 2021. Some on TikTok even believe that BTS is successful because of the privileges from their big company.
Most importantly, did Somi ever want to be in a group post ioi anymore? She left JYP in August 2018, and Itzy debuted in February 2019. And she's just a year older than Ruka, right? She could have joined BM if she wanted. Now, she's in a very comfortable position. She's still very relevant with a lot of CF deals, while not having to work as hard as groups like Itzy, with tight schedules, tours and those crazy choreographies. Girl obviously loves her chill idol life.