Developing new stacks from top to bottom is crazy expensive and time consuming. Modern OSes have benefited from many decades of optimisation and you can't repli

Developing new stacks from top to bottom is crazy expensive and time consuming. Modern OSes have benefited from many decades of optimisation and you can't replicate that overnight. Even a far superior new architecture will start out worse in almost every way and take a long time to catch up. Just look at Apple's rollout of Swift. Early on it was slow and painful to use for a long time. In the last year or so it's really matured a lot, but it's been a long road and we're still not there yet for a lot of use cases.