I’d imagine it’s a little bit of both to be honest.

There’s definitely algorithmic prioritisation for new content but I think it’s also a bit of a “seek and ye shall find” moment happening.

As an anecdote, very recently I had the opposite thing happening. I was researching something about React and noticed one of the comments ( still applicable actually! ) was from 2015. My head exploded when I realised 2015 is actually 7 years ago so for a short time afterwards I just kept noticing old comments or old content everywhere.