They did basically achieve it. There's one missing component though: the kernel. One big reason kernels have to be gigantic nowadays is the stupidly high diversity of hardware interfaces. Every USB device, every graphics card, network card, printer… has its own peculiar way of talking to the rest of the computer, and that shorcoming has to be compensated by bolting a driver on top. For each OS.

See Casey Muratory on the 30 million lines problem: https://caseymuratori.com/blog_0031

Solve that, and then ideas from VPRI can shine.