Game-theory view is that any organization that would like to push this would have to spend enormous amount of resources to reinvent almost anything that has anything to do with TCP. Remember, it is implemented in hardware in many different types of devices, stacks, applications, it permeates almost anything. The application I am working on right now which has lived for over a decade and will live for another has TCP artifacts all over it. Who's going to want to fix it when it gains maybe a tiny bit of additional performance?

There aren't very many applications that have TCP as their single biggest performance problem with best ROI. Almost every is integrated with bunch more other applications over TCP causing chicken-egg problem.

Maybe Google could do that? IDK. They would maybe do it after they have reinvented almost everything else in their DC infrastructure.