"Net" means "no"
So pronet = not a pro
kind of, the traditional route was to play semipro for a bit, but recently kids like bymas, broky, ropz etc have been plucked straight out of fpl. by the time you make it to fpl the skill gap is virtually non existant, its more about positioning and game sense instead of raw aim. if you want proof that pug stars are as good as pro players, look at the fact that literal major winners have been kicked from fpl while young kids keep joining