Bluesky hit 15 million users this week. And then 16 million. The vibes on Bluesky are immaculate, and it seems to have a real and renewed chance to be the place that replaces Twitter for a lot of people. But then there’s Threads, which grew by approximately one Bluesky just this month. There’s also Mastodon, which is still hanging around, and of course there’s X. There are ...