Exactly this. Every non-shit mobile game I ever found turned out to be a port from either PC or console.

I've not found that to be necessarily true, since some games just don't feel that great translating over to a touchscreen coming from its basis being gamepad. I've bought lot of games from spare Google rewards points like Dead Cells which is a good game and playable but not really comfortable enough for me to play it on mobile, and getting controller out feels like I'm defeating the point of mobile game since usually it's something I'll play when all I have is my phone. Not going to stuff a gamepad in my pocket.

Games that really do try to make use of the touchscreen in a great way I've found to actually be Nintendo DS games that were specifically designed to be played entirely with stylus. Other actual mobile games have felt more like gamepad games trying to translate over stuff to the touchscreen with non tactile elements. Kind of works, but feels off. Unless its like an RPG or a game like The World Ends with You which was made to be touchscreen from the start. That seems like a good port.