I think the biggest issue is titles; what people expect of mobile games, perpetuating itself into a weak catalog of original titles, with a few good ports. Mobile games are largely designed to be heavily-monitized, Games as a Service, and/or gacha titles… profitable design choices, but not because they make games better.
Having a more standard control scheme would help get more ports of console games, but I’d love to see more mobile games that use the existing interface/formfactor well. Pokemon Go circa 2018 was a good game that only works on mobile, and I’d love to see more of those.