I've got 1322 communities blocked myself π. Still plenty of content to view using either the 'all' feed or my front page.
I also use filters a bunch, which helps with stuff like excessive posts about certain creeps in tech or getting spammed with quasi-duplicate posts across multiple communities that I otherwise want to see content from.
Got a few instances blocked as well - seems like Lemmy has a pretty good set of tools to customize content.
I block by keyword using filters in the Connect app myself - works great!