I make good use of the block user feature. I've done enough self house cleaning that I don't really get a lot of spam. I spend about 10 minutes a week blocking user that are obvious bots and it seems to work well. Checking their karma credit and length of time they have been on the site helps.

Also u/In-the-clouds made a good comment last week about using the friends button. I've been pretty generous with it and it's working good for me. The trick is to add everyone even if you don't really agree with them. The strength of this site is it's openess to allow everyone to speak even if they are an asshat. If you are just looking for an echo chamber there are plenty of other sites for that.

I think one good feature would be to make it a lot harder to create a new accounts. If you could make it difficult enough that most bots can't auto create accounts that would make a big improvement.