Communities have clear benefits, because the people you want to see your work, and people whose work you're probably interesting in, are more likely to gravitate toward communities you're in.

But I have to say, I expect I'll see enjoyable serendipitous discovery in communities I'd normally not be a part of, and in general feeds or just browsing around.

Popping into various communities might help prevent one from stagnating in echo-chamber bubbles, too.