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
It allows me to browse an everything feed from multiple accounts.
Therefore for example I could get my beehaw communities in my feed with this account's too and when I open a post to comment it just pulls and submits from the appropriate account.
So for example if it was a submission from lemmy.world it would be pulled from my sh.itjust.works account and would submit my comments from there but a beehaw post would do the same from my Beehaw account without having to actually manually switch between accounts.
I'm not explaining it well. Just get an alt account that's defederated from lemmy.world and try for yourself.