It's as much simulated gambling as Balatro is

You are gambling your time (essentially the same as money) on the hope of a dopamine rush experienced upon winning (also worth money).

There is a history of solitare and gambling. https://greatbridgelinks.com/how-to-play-canfield-solitaire/

There is a version of Solitaire that is a gambling game. https://en.wikipedia.org/wiki/Poker_squares