I think you're looking at the wrong abstraction level. You're thinking on a node (computer) basis. Even on a single computer, many of the things that happen are distributed. DMA controllers, input interrupts, kernel-forced context switches, there's a lot going on there but we still pretend that our computers are just executing sequential code. I agree with the OP and think it's high time we treat the computer as the distributed system it is. Fuschia and GenodeOS are both making developments in this direction.