I hear TikTok is on the decline, and arguably the forced change of ownership is a sort of regulation. Instagram is owned by meta who has an interest in not letting it overtake Facebook in terms of popularity I imagine. It seems like a sort of hedge against other platforms mostly, but I really don’t know much about any of these platforms tbh. I use YouTube very heavily, but have only used twitter, Reddit and tinder in the distant past. I’ve never been on Facebook, TikTok, snap, etc… To me, irc and usenet were greatly superior and I’m waiting for people to return to their senses.