That doesn't make sense though unless there's a directory of recommendation engine or search engine for interesting people. Otherwise it means that I'm supposed to follow people that I already know, which is ridiculous because I don't want yet another channel to see the same stuff I already see.

On HN there's the front page where interesting stuff is curated algorithmically and smart people that I don't follow or know perviously make interesting comments on that stuff. Mastadon doesn't seem to offer anything like that.