[PaulHoule]

An algorithm doesn't have to reward engagement or time spent on the app. It can reward or punish anything at all -- and that's what it is about algorithms.

My feed reader (that I wrote myself) rewards things that I thumbs up and punishes things that I thumbs down.

[bluebarbet]

Is this mysterious feed reader one that you made yourself?

I agree about the need to have some means of filtering. This is a major weakness of RSS, alongside onboarding and discovery. Algorithms serve the purpose of filtering well. The problem is their opacity.

[PaulHoule]

What people are calling an "algorithm" is really a heuristic.

In the public discourse over "algorithms", the definition seems to be "something that maximizes your (time on site|outrage|clicking)" and not the real definition

  In mathematics and computer science, an algorithm (/ˈælɡərɪðəm/ ⓘ) is a 
  finite sequence of mathematically rigorous instructions, typically used 
  to solve a class of specific problems or to perform a computation. [1]

By that definition any well-defined process that creates your feed (sorting chronologically, alphabetically) is an "algorithm"; in the machine learning age it is easy to make an algorithm that selects for anything at all, except for the capital-T Truth.

[1] https://en.wikipedia.org/wiki/Algorithm