It's impossible to play esports competitively if you aren't in a good physical and mental state. You can try but you will be playing way below your peak, to the point that it stops being enjoyable.

Rocket league for one receives sponsorship from car companies, nike, movie studios, and even football clubs regularly. Their nike paint finishes were selling like hot cakes.

Notice how the game company is the one making the money. Tournament organizers, server admins, production, casters, players, managers, etc do not have a sustainable source of money. Often people volunteer their services and communities fundraise money to fly teams in to compete because that's the only way they can afford it.