Social networks are driven by social aspects who is going to each of these services why and you know what forces are are moving them there. Blue sky was backed by money from rich people it's put that way right i don't know if it's adventure capital thing or whatever but like jack dorsey's rich person they've got not a lot of money but millions of dollars right behind their protocol. mastodon has more applications than blue star practically speaking  and despite the fact mastodon makes you pick a server for enjoyment as most of us are mostly off of it some people are still there. If you ever tried to sign up for mastodon I got scared away by the thing where your