I signed on to https://social.photo/. And I'm sure I had darned good reasons for doing so at the time. LoL With federation, I'm not really sure it matters which instance one signs onto, as long as it's not some tankie/nazi crap, of course. And of course one could self host one's own instance.

It appears to me that, because of the absence of advertising, it is incumbent upon individuals to 'evangelize' and spread the fedi-gospel. :-D