> I ended up forgetting to visit Lemmy or Pixelfed or <whatever> because I had 2-3 times when I opened up the app and saw the exact same content, giving me a feeling of "nothing is happening here" and thus, I didn't need to check in.

I think this is the point the OP is making though, there's little to no actual benefit if the content doesn't change often. You probably never forget to check HN for example.

An RSS reader linked to this via a browser extension might be a more useful interface for feeds that aren't updated as frequently.