Yes, that's exactly it: the discoverability. I joined a small to medium server, and I thought that Pixelfed's search would be like the one in Mastodon: search for a hashtag and get results from all of the other federated servers, but no. The search function doesn't seem to work with hashtags, so subscribing to one is a pain.
And the available apps are not very good. And the official one hasn't been released yet.
Besides Lemmy, I have a Mastodon account. I'm not very active, though. I'm also on BlueSky, but because most of the post where uninteresting to me I uninstalled the app months ago and hadn't logged in since. And I'm exploring Pixelfed, but my experience hasn't been so good.
"Updated README"
In Mexico they are:
Melodysheep moment. Their content is simply amazing.
What you're looking for is called RSS. Install a RSS client, subscribe to some blogs or interesting sites like Aeon, Psyche, Nautilus, Longreads or Hacker News and add them to your client. Then you can scroll mindlessly through your own curated list of educational content.
I mean, I mentioned that my experience with Pixelfed has not been the best, since it lacks content and discoverability. I wouldn't sign up again to Instagram (I deleted my accounts years ago), but it's obvious that it has orders of magnitude more content, and maybe the recommendation algorithm can be useful sometimes.
Personally, even if I don't want to, I have to use WhatsApp since everyone in my country uses it, even government offices.