i'm not that old but i did grow up with a taste of the old internet, but i never really participated in platforms like livejournal, xanga, geocities, or wordpress. i don't even know what ancient twitter and tumblr were like really, i sorta missed the boat on everything that wasn't forums and IRC.
cohost may be "a rest home for millennials raised on the old Internet" as @kstarling put it, but i think that also makes it sort of a living museum for young people to experience a taste of the the old internet (the good parts of it anyway).