Open Source is not immune to monopoly
humancode.us
humancode.us
That being the case my understanding is splitting this project up is not only a technical challenge but a legal one.
You could make a common API for driver code, this would make the main driving force of linux much weaker.
Nvidia tried to stay out of tree for years and was dragged kicking and screaming upstream because they needed the reliability.
I'm saying the very thing you are calling out as a problem is currently what is forcing everyone contribute to the mainline kernel.
Without centralized leader ship the facturing of the linux kernel would be a disaster.
"...The recent fiasco involving Linus Torvalds running Linux like the privileged man that he is and entirely missing the central points of the arguments made by people who don't enjoy his kind of privilege..."
It was his 'privilege' that led to the technical competency of the project that is now enjoyed by many.
Attacking someone's 'privilege' is the lowest form of argument.
Its open source, go start your own project and stop complaining.
No one is forcing you to use Linux any more than anyone is forcing you to use Windows or macOS.
But even there the issue wasn't the existence of monopoly per se, but with the (ab)use of the monopoly to also capture the emerging Internet browser market.
Even if Linux was a monopoly that would not necessarily be the case for ever, as the example of the Windows monopoly demonstrates. But Linux isn't even a monopoly today.
I'm not even sure I'd describe it as a monoculture either, if it was that would probably have accelerated its growth even more. Imagine where Linux would be if it were like FreeBSD in having only one distro, one libc, one set of system libs.
You're starting to see it as a server backend lingua franca but even there, there are multitudes. And there remain a great number of organizations that run on one of the BSDs, Windows, old mainframe OS, and so on.
Anyway, Linux is a technocracy. Actually, a technical meritocracy to be more precise, rather than economic or political dominance.