A handful of them. The fragmentation of lemmy is yet to be improved. It is common for me trying to subscribe to remote community that the remote community is not found or the instance is in "Blocked Instances".

This is bad for general users since they will not be patient or bother to open multiple accounts across multiple instances.

https://webapps.stackexchange.com/questions/170872/how-can-i-subscribe-to-a-remote-community-on-lemmy