Probably move on to YouTube Shorts or Instagram reels.
Likely YouTube. While neither are great, between Google and Meta, Google's got the better reputation. YouTube also has a larger audience, because it includes a ton of users who wouldn't fall under traditional social media usage. Reels might be used as a periphery platform to drive more people to their main channel on YouTube.
Any TikTok creator who moves to Instagram full-time is either shooting themselves in the foot, or got a good contract from Meta.