https://www.gamasutra.com/view/feature/131494/behavioral_gam...
Rewards and punishments are used to create schedules. They make player do the things the company wants them to do when they want them to do it. A simple example:
- playing every day rewards the player with bonus items
- taking a break punishes the player by making them weaker relative to other players
And of course there are those wonderful companies which reward players that spend money and punish those that don't.
WHO already recognizes the existence of a gaming disorder:
https://www.who.int/features/qa/gaming-disorder/en/
It's only a matter of time before this industry is regulated.