Ah right, I don't play games on mobile, but I think there are still mobile games with simple straight-forward pricing models. For example the Baldur's Gate series got released on mobile (already a few years ago), and Wadjet Eye Games releases most of their adventures on mobile too I think. There are undoubtedly others.

But I guess they're harder to find/more rare. As others mentioned, most people spend nothing to little on these "free" games, so as a no-spend gamer you can choose between 1) free, or 2) pay $10 (or whatever they charge) to play a game. Not necessarily a hard choice if the "free" game is "entertaining enough".