The short answer is Lemmy has a theoretically near-infinite number of communities and no “engagement algorithm” so it’s up to us to curate what we want to see by blocking the communities we know we’ll never read, or, in some cases, blocking users that we can’t stand.

(Alternately you could curate just the comms you want and only browse “Home” communities)

If you want no politics there’s a number of hobbyist and nature-oriented communities, I’d start there.