And how many dozens of indie games came out that same week whose studios folded afterwards? Or how many devs didn't even release their first games because they ran out of money during development? Or how many smaller studios who were making fun games got irresistible offers from big studios to buy them out? What about the engines that are becoming increasingly more hostile towards devs?
The problem with the alternatives is there's no draw to any of these sites. Like people aren't going to Mastodon because it has some amazing features that everyone wishes Twitter had, they're going because they don't like Musk.
There's so much on Twitter that these other sites don't have that it's hard to justify leaving. There are so many politicians, reporters, athletes and teams, bands, artists, etc all on Twitter. I follow hockey pretty closely and every major trade that happened last season was first reported on Twitter. Will I get that breaking news on Mastodon? No, so what is the draw to Mastodon? What does the average user get out of moving over?
What do content creators get out of moving? An artist can have years of their work on their account as a portfolio to draw new fans and get work, but if they move none of those posts show up on Mastodon. Now they have to post their entire portfolio again, and that doesn't even guarantee that their audience will follow them. Now they're on a much smaller website with a much smaller audience and they're probably not going to get the same exposure or opportunities that they had when on Twitter.