You get what you pay for. If you download a free game, then of course it's going to be full of pay-to-win microtransactions. Although there are issues with greed in some larger games run by big companies, the reality is that game devs deserve to earn a living too, and that means at some point a game needs to be paid for.

There are still plenty of good quality mobile games out there, they just don't tend to be free to download. Back when I had more free time, I actually got good usage out of the Play Pass on Android, which was £5 a month and gave me access to a catalogue of excellent mobile games with no microtransactions at all, the vast majority of which were single-player, offline games. Literally the only reason I'm not still subscribed is I just don't have time to play mobile games at the moment - the chances of me subscribing again over the summer when I'm not at uni is high.