I think we'll eventually realize that this line of thought is the same as tobacco company apologetics. Napping isn't A/B tested for maximum addictiveness.
One of the things I enjoy about many (albeit, not all) cozy games is the ability to step into them, step out of the game five minutes later, then pick them up several days later. Sure, some developers are going to do A/B testing to monetize every last second of game play. That said, I doubt that many of those games would fit into a realistic definition of cozy games simply because most of them exploit the player's emotional state.
My point is that humans aren’t wired for 100% uptime, and filler activities are somewhat necessary. Any leisure activity is “filler”, and we don’t have to AB test something for it to be maximally harmful. Playing Fortnite is objectively less harmful than hurling bricks at buses, and only one of those is AB tested.
We're talking about two separate things. I was talking about being able to play a game for 30 minutes (or even 5 minutes), then set it aside for later. That could be later in the day, or several days later.
Quitting gaming altogether wouldn't have many benefits in my case. I only play on weekends, and usually less than an hour per day. It's not that I'm boasting about a lack of filler activities in my life. I have them. They're just elsewhere.
