It's too expensive to optimize for every device. Agreed. The "solution" I suggest just allows you to avoid the lowest common denominator - it doesn't make it

It's too expensive to optimize for every device. Agreed. The "solution" I suggest just allows you to avoid the lowest common denominator - it doesn't make it cheap, or even viable for all devices. But for the most popular devices it should be economical. I guess it depends on how fragmented things get - but I don't think a phone monoculture is any kind of solution, it just shifts the problem.