You're right: It might have been so much easier to leaveTwitter if, as soon as Elon Musk bought it, journalists and authors had reached a consensus about which platform to move to.
Let's say, if big group like the Authors Guild (or all major newspapers) had asked their writers to move to a certain platform. Then we all could have moved with them.
What happened instead was that the new platforms raced ahead of the writers: They began springing up before writers could organize. And a lot of them made rules that made it impossible for everyone to gravitate to the same one: You need an invitation to join Bluesky, you had to get accepted by me.dm, and Threads had too many unsavory associations with Meta.
Now we have an unsatisfying patchwork of platforms that would be very hard to undo. I'd love if it the journalists at least could agree on one, but there's so much water over the dam here that I'm pessimistic about the prospects of its happening,