I guess you need to do some more research on how Lemmy works.
You can follow any community from any instance. For now you could create an account at some lesser populated instances, I had one on lemmy.ml, made another account on monyet.cc. It's a minor inconvenience that you have to subscribe to communities but other than that my experience with lemmy has been very good.
I already have Mull for everyday browsing and stuff, but for PWA Mull seems a bit slower. I do use native alpha for PWA but Voyager which is a lemmy web client doesn't work well in native alpha.
I guess you need to do some more research on how Lemmy works.
You can follow any community from any instance. For now you could create an account at some lesser populated instances, I had one on lemmy.ml, made another account on monyet.cc. It's a minor inconvenience that you have to subscribe to communities but other than that my experience with lemmy has been very good.