I never got much into mobile gaming, but have recently been having a lot of fun playing PC or console games on my phone (using a controller) with streaming services. I've played with both Geforce Now and Xbox Game Pass and (at home on my decent cable internet connection) it's working really nicely. I also have the Nvidia shield, so when I do want to game on the TV I can pick up where I left off very easily.

If you're looking for a game to play on your commute it's probably not going to work, but for at home on the couch it's great.

My phone runs games up to ~PS2 in emulation, FWIW.

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".