The other day I called the politics stream an “echo chamber”
But your definition is more concise and to-the-point
That said, if you sort politics stream by “new” you’ll get a much wider variety of content
But the fact not a single one of those non-alt right memes has ever, ever hit the front page is very telling
One time I achieved the feat with a bland centrist meme praising MLK on MLK day. They had the decency to upvote that. That’s about it.