I've been drawn to kbin, it is part of the "Fediverse", so you can see kbin, lemmy, and I believe also mastodon posts from it. If you just anonymously browse to https://kbin.social/ (the main instance right now) you'll have something similar to the reddit front page, content from a bunch of different instances. It is definitely still a little rough around the edges, but considering it is one dev and the first commit was only two years ago, it seems pretty good.

Is it automatically pulling content from all other instances??? That was not clear to me, I though it was some form of cross-posting and required someone to submit things.