Most people don't want to farm endless hours on path of exile or build strategies to kill demon soul's bosses or do difficult content on meat boy. they just want to do ripetitive simple things (btw that's why crypto isn't mainstream yet, too much works to do)
Just a quick game while commuting in the metro,bus,tram or etc. is wonderful i think, time taking strategy games or breathtaking graphics is not important in mobile gaming or not in the first place.