The Indie Web website up there actually has protocols to do most of what people do for social media, in exactly that structure. It’s enough of a pain to set up that I don’t see it becoming normal, but the amount that I’ve set up for my website at least works…
I can’t vouch for anything about it, since I’ve never done more than look and bookmark the page, but Vidzy at least exists and has an instance that plays one short video…