One also has to take into account other revenue streams that Youtubers will often have. Most channels nowadays will start up a Patreon account once they get a core following, and even a monthly dollar per Patron is more than all the adclicks that viewer would give. Merchandising is also big (1 T-shirt > 1000s of views), and bigger channels (100k+) can get a decent amount of revenue through sponsorship where they give in-video advertisements (like what Squarespace and a lot of VPNs do).

After the instability of Youtube's ad platform this past year ("Adpocalypse 1, 2 and 3"), many on the platform have given up on the idea of depending solely on adclicks as it's just too risky to leave your future to the discretion of a black box algorithm.