Lemmy sorting is still interest based if your not scrolling through /all , it’s just that those are declared interests, you subscribe to the tennis community, as opposed to inferred interests, the algorithm figured out you like tennis based on your watching habits. It’s still curated it’s just self curated instead of algorithmically curated.
So I guess you could say it stops at how the interests are compiled and whether the interest was given explicitly by the user but then you get into how a user understands certain actions like likes. Do people like something to just give feedback to the poster, then it shouldn’t be used at all. Do they like something because they want to boost it and have their wider community to see it, then the algorithm can take that into account when giving it to friends / followers. Do they like something because they want to see more of it, then the algorithm can use that information for recommending things that user will see. My guess is people use it as some combination of all 3, and as long as the social media tells its users at the beginning that the heart button is all 3 they could get away with saying there algorithm is explicit while not changing much.