I did a poll and nearly 30% of the people who voted said they used Sync! It's stayed around that percent the whole time too!
EDIT: Here is the poll I forgot to put this here like five times lol https://strawpoll.com/wby5A21R1yA
You do know the difference between communities and instances, right? And you do know how federation works, right? Also, based on where you look, !asklemmy@lemmy.ml is either the largest or one of the three largest communities on lemmy, so I don't think there's much bias in there