There are already plenty of devices, from old phones to vacuum robots, where we have that or near enough.
Technically, we know how we could maintain/re-flash these devices.
Yet, we don't. Why? lack of standardization, specially the boot process in non-x86 platforms.
Having to maintain per device images is not really practical at scale.
I also don't get why people claim NT is "better." Linux is a modern kernel under very active development.
There are a few interviews of Dave Cutler (NT's architect) around where he explains this far better than I am here.
Overall, you have classic needs and if you don't care about OSS (either for auditability, for customizability or for philosophical choice about open source), it's a workable option with its strength and weaknesses, just like the Linux kernel.