I think perspective is key here. Setting aside the low barrier of entry that can't possible keep the truly dreadful garbage out, on mobile you're super limited on your input method (touch screen and not so great motion controls). This tends leads to devs gravitating towards the sort of genres that were historically plagued with low quality shovel-ware on platforms like the Wii. As others have said, true gems exist, although I'd argue that the best of the best do tend to ports from more capable platforms. Titles like Dicey Dungeons, Slay the Spire, and others along those lines have rich play mechanics underneath of the simple touch interface. It really all depends on how how far you want to dig, and how deep of an experience you want (there are hundreds of good enough match 3 games if that's your jam).