People are nailing it here -- it's not the "OS" per se (heck, look at CP/M or original unix and this gives you a floor) -- it's the drivers and the required Standard Pieces: DMA, memory protection, TCP/IP, BLE, WiFi, Ethernet, GPU, USB (+ vast USB drivers), etc. Lotta 'standard' software must work on any new OS + drivers for all that hardware that is always changing. Great 'fun' .... Now, I do think Minix had a chance for a very short window, but lack of resources made sure it's now only an OS history footnote. All because a microkernel sucks 3% performance away from monolithic kernels. We are confused as an Industry... Performance uber alles -- that has just GOT to get fixed. Security; maintainability; simplicity > performance; or rather, those are worth some performance degradation.