problem is the kernel is sitting on top of a binary blob, and that manipulates the access to the real machine.
we shouldnt be so worried about the kernel, we should be concerned about what the binary between the kernel and the hardware is doing/notdoing , and what degree of control do we have over that layer.
A cloud provider and your personal machine are different things with different considerations. The advantage of using Linux on a cloud provider is primarily to prevent vendor lock-in and be able to move to a different provider or a physical server under your control as needed.
Using Linux on a personal machine is primarily so you can trust your machine to serve you and no one else. This is defeated if Windows or backdoored firmware is running below Linux.
Note that the no lock-in benefit also exists on the desktop and because of that it makes sense to switch to Linux on a machine that requires proprietary firmware as an intermediate step to moving to a better machine like those from https://puri.sm/
Cloud providers have no profit motive in breaking your trust. I fully believe an OS-vendor for personal computers would, especially if there's almost no alternatives.