I don't care much about mobile gaming, and when I play something to kill time on it, it's often Minesweeper, Sudoku, Dominoes... back when I first got an smartphone (2019) I tried out several games, mindnumbing idlers, big-IP gacha-crap, they all look pretty much the same and looking at the store today I can't find anything that looks remotely interesting... I mean, I just saw this one Tomb of the Mask but then at the reviews you see people saying this game used to be good but now it has aggressive monetization on everything.

I remember having some good time with Autochess, an Elder Scrolls card game and some Warhammer 40k games, another fun game I played for a bit was Magic Rampage, and I also really liked Stranger Things: The Game (I just saw it was renamed to Stranger Things 1984), but it has been some years since I last played so I don't know if they became an Ad hell as well.
Back then, I bought two games: Solitairica - which I recently reinstalled and it's still great. And Rebel Inc. - which I also recently reinstalled but they released several packs of premium content so everywhere you tap they are trying to sell you something... and since I last played they also added a new difficulty setting that is looking very p2w and it's quite sad. Night of the Full Moon is another game I liked a lot, I tried to buy the full game back then but I was getting an error in the store and gave up, I might buy it now.