Then, there is TikTok algorithm which is a common critic of the app but is how you get a never-ending flow of content which isn't uninteresting enough for you to turn the app off
I think there needs to be some kind of discovery algorithm for new users with an empty feed (or even existing users who just wanna find something new) but a federated alternative doesn't need something as powerful as the tiktok algorithm to be a decent replacement. It doesn't need to surface a "never-ending flow of content" because it doesn't have a financial incentive to keep you in the app endlessly.