The Fitness Marshall has over a million subscribers and over 150 videos on his channel. His paltry take after three years of work comes to about $20 a video after record labels and everyone else take their cuts.
The folks who benefit most financially from his channel are the record labels, since he uses copyrighted music:
So with us, since I believe in using real music that we hear on the radio – I don't want to dance to music I don't love – so with our videos what happens is: we put out the video, ads run on it so you see a bunch of ads when you're watching our videos, and then the record label comes in, they take all of the money, and we are left with zero. ZERO!
That's why creators have to supplement with merch, subscriptions, touring, and donations. YouTube alone won't usually cut it, especially with inscrutable demonetization rules and other complex and confusing unwritten aspects of how YouTube treats creators.
Image: YouTube screencap