I just browse their communities from another instance. It’s not like you have to be a member to engage with a particular instance. It might harder to find an instance’s community on your instance because nobody on your instance has subscribed to the community, kick-starting the feed to start populating with its content, but using the outside/3rd party instance/community search tools, I’ve subscribed to several communities across several instances, all from my preferred instance account.
The only benefit I could see to being specifically on Beehaw is that you would be somewhat shielded from content coming from instances they defederated with; and it’s a big blanket ban. Maybe some of the communities on a blocked instance aren’t piles of shit. I, personally, would rather start with an entirely open instance and block what I don’t want to see myself, over letting someone else make that choice for me. There are very few instances I would block in their entirety so far that I’ve seen.