I will just say that one big advantage of Linux compared to other kernels is the fact that the same Linux kernel that your average Joe is running on their own machine, is the same kernel that CERN is running in their experiments.
Improvements to any area of the kernel get upstreamed and sometimes those affect (and benefit) various setups other than the intended machine, this is mainly due to the nature of open source and shared codebase, Linus himself explains it here:
https://youtu.be/MShbP3OpASA?t=1335
https://youtu.be/MShbP3OpASA?t=2280
I think this is more than what any company could ever dream of achieving, they might just lack the resources to do it.