Well, here is your actual OS then. You named it "hypervisor", and changed the system interface, but it's still there, revirtualizing the access to hardware and ensuring separation of different users/applications/unikernels.
Or if you're more familiar with embedded, like a BSP or RTOS
Unless you're literally running a single application on a dedicated piece of hardware in which case... yeah, sure, you can do the OS-as-a-library schtick. But you could do it 10 years ago, too.
The point is all the other things: total number of lines of code, permissions and security, memory management, drivers, process mgmt, it all changes.
I do know that AMD has done more in this space. When I worked at Google there were (other) people on the Stadia team doing this. And some open source bits out there that I've seen, including from AMD.
Unfortunately, my real world work... and most real inference etc work others are doing... is on CUDA/NVIDIA.