What I don't understand is why it is so much effort to use linux on a phone. Surely these 8 core ARM monsters these days should be more than enough to handle a full kernel. Hopefully it's not a driver issue where manufacturers only contribute the necessary drivers to the android kernel, not the linux one.
Battery/sleeping is the main challenge I believe, not processing power. Linux laptops still struggle a lot with sleep. And Windows laptop too btw.
Android is running on Linux. It's not the kernel that's the problem, it's the application layer.