I really dont understand why we cannot just go back to chronological as a default. This is how I use X/Twitter, and anything else that lets me just go chronological.
It's because the majority of users are being fed more content than they can consume, whether that's through a large count of follows or global search results or a discovery tab. In that case, you need some method by which to decide what subset of that content to show to the user. Chronological ("show me the latest 50") is one option, but is it the best, for however one defines "best"? The people running these things seem to think it is not the best, for however they define "best", so we see the various discovery algorithms and all their associated pros & cons.