I looked at their individual page (darkpattern.games/…/psychological-dark-patterns.h…)…

If deleting the game and starting over from scratch sounds like a horrible idea and a waste of your investment, then the game has Endowed Value for you. The more time and money that you invest in the game, the more value it has over a fresh copy of the game.

So I guess they are referring to is something more transactional… for example, if I spent $100 on a gacha game or loot boxes to get a bunch of ultra-rare SSRs. I’d be pretty compelled to keep playing since I’ve already spent so much money on it.

They are not counting, for example, that I get hooked on some weird roguelike game because I genuinely want to get better at it but can stop any time. And if I lose my save file I would still happily start from scratch again (which, hilariously, a pattern named Infinite Treadmill is marked for both Slay the Spire and Balatro… www.darkpattern.games/…/infinite-treadmill.html)