If Trump had swithed to something else while he was president, it would have made that something else relevant, added hundreds of millions of users to it as even people who hated him were obsessed with reading his tweets, and that something else would today be a real competitir to twitter, if not already bigger.

A lesson for the next populist. Use establisment media / social media to get elected - then switch to a platform that's sympathetic to you and your followers once you have everyone's attention.

Yes you'll probably lose followrers at least in the short run, but you'll gain influence. And followers is just a number.