Technically sort by top and some by new are algorithms. But that’s not what people talk about when they say algorithm with regards to social media it’s secret sauce engagement based algorithms used to show content.

The active and rising sort options are fairly simple and open source so we know exactly how it works

lemmy uses

Does it?

Probably because there exists a bit of a rift in the technical term 'algorithm' and how it's commonly used in discourse. Technically it describes both:

1. An open-source algorithm that assigns a simple score based on votes, score and age, where two users subscribing to the same communities will always have the same result.
2. A hidden algorithm that's based on an unknown amount of invisible variables, many of which are based on user-tracking, and tries to maximize time-spent at all costs.

While OP (hopefully) intended the former, most people immediately think of the latter when the term is used. Personally I'd like to see an implementation of the former as well, as a simple way to get up speed on the most important things that happened over night for example, before switching back to chronological timeline.