What suggests to you smaller ones are the most problematic?? When I think of younger people interacting online I think of big places like TikTok, I don’t think of a random mastodon server.
The issue is not that a dog turned up to get a picture of their face, it’s that if I have a picture of your face now I can pretend to be you. Woof.
Think about 8chan and other underground social sites that are breeding grounds for radicalized youth.
Apple has pictures of all of our faces. Companies have your voice if they want. It’s too late to worry about that. Anybody can be you if they want to. Eventually they could do it with a single photo if not already.