Meanwhile, my feed is photographers, linux people (because of course), and a weird confluence of unobjectionable academics. I saw what you're describing in my brief visit to the Lemmy world, and I absolutely know that there are hostile and degenerate Mastodon instances, but most of the big instances have defederated with them, so I don't get sniped by any of the freaks.
Now, I do pretend the global list simply doesn't exist and focus on the local instance list and people I follow. I don't know of anyone who uses the global list. I also tend to follow hashtags rather than individuals. (I'm 100% sure that twitter would show at least as much garbage on their feed if they didn't filter, especially these days. This is not an argument for Twitter's style of filtering.)
Now, I do pretend the global list simply doesn't exist and focus on the local instance list and people I follow. I don't know of anyone who uses the global list. I also tend to follow hashtags rather than individuals. (I'm 100% sure that twitter would show at least as much garbage on their feed if they didn't filter, especially these days. This is not an argument for Twitter's style of filtering.)