There is no way for a user to block whole instances, there is no way to know if you've been banned from a community or instance, it's extremely easy for people to evade bans and blocks, you can't make private communities, armies of extremists are brigading other instances and they're exploiting Lemmy's flaws to do it, the list goes on and on.
Lemmy blows, but give the rubes time. They'll figure it out.
Those are just cop-outs. They need to be hard-coded features on the original Lemmy app. If we have to rely on third-party apps for it, we can and should just use another fediverse app entirely.
I hope someone forks Lemmy at some point.