I can't help but think I'd buy 10x as many games on mobile if there was a way to filter out all in-app purchases (other than pay once: add-free forever no more asks to buy)
This is why I love Apple Arcade. No ads, no in app purchases, and plenty of classic and big name games too. They aren’t all good, but there’s plenty there to make it worth it.
The best game I've seen for this is WazHack. It is free to download and play, but only to a certain depth. From there, if you want to go further, you pay for whatever type of character you want to use. If you only want to use one type of character, like barbarian, it costs 1$x. If you want to play all 8, it's 8$x.
Straight forward, you can play it to see if you like it, you can play the different characters to see if they match your play style. No other purchases needed.