I often comment on things I like.

Regarding community, if you don't find what you want, make it. I've made various ones over the years, of which allbingo and crowdfunding have succeeded pretty well.

I also use recurring posts to build community: Good News, Hard Things, and Cuddle Party. Folks are welcome to riff on those in their own blogs.

There are active blogs, there are lots of people who want more community, it's just a matter of finding and connecting them.