I follow many tags and have yet to see any of this stuff on them minus the crypto stuff. You must be following the wrong tags.
Discussion
Simple tags like #memes can attract it with too much regularity. The more extreme it is, the less common, but the more tame stuff still isn't exactly uncommon. Maybe I just have poor relays configured, but that isn't really a good answer because there's no easy to find information on choosing good relays, probably because it's such an evolving topic.
Not to mention due to the lack of a centralized algorithm, Nostr content is much more unpredictable than on X.
The problem is not the relays, the problem is that you seem to be one of the usual fediverse breed of hypersensitive loudmouth.
This isn't an echo chamber.