https://en.m.wikipedia.org/wiki/Fourth_Estate
Just like within actual government there's supposed to be balance of power between different branches or houses, there's this idea that the role of the press is to hold governments accountable.
(More of an ELI12, but that's the gist of the idea)
Somehow I manage to be both. My alcohol tolerance is very high (which is great... I like a little buzz but never want to be actually drunk), but for me, one toke is over the line.