I make great use of filters on Mastodon and it’s improved my experience tremendously for much of the same reasons over there. On Lemmy I use Voyager so it is an option.
I’m hesitant to do keyword filtering because I also host an instance, and I’m concerned that I’d miss something that needs to be handled. I didn’t really care so much about wanting to keep an eye on stuff until people were posting malicious content affecting other servers a few months ago.