After attracting 2 million users in its first year of operation, Bluesky has grown another 400 percent with some recent help from Brazil and Elon Musk. Are these monthly or daily users, or just account holders? Nobody knows! But it still has a way to go to match X’s estimated 250 million daily users and Threads’ 175 million monthly users.
Comparing users to MAU seems disingenuous. The fediverse has ~12 million users, according to fedidb and around 1.1 million active ones.
Most of them on Mastodon.