Isn't #Bluesky working on something similar tool?

Either way, I see such tools as problematic. Even if you assume that the intentions behind it are benevolent (which is a clear "no" for #X, and a strong "maybe" for Bluesky), such a system represents a black box - you do not actually know whether the system actually filters posts in a way that is best for you.

I prefer to stick with a timeline-based system.