If we could write a whole new unix-like operating system from scratch today, such that nothing in it has to be backwards compatible with old hardware or standards (only has to support modern hardware to reduce complexity), what are the "lessons learned" and unnecessary baggage?
By operating system, I mean everything from the kernel to the final applications that your desktop environment comes with by default. For example, would it be a microkernel? Would terminal emulators follow a different standard? Would ascii be abolished and replaced by unicode? Would the kernel be written in something other than C? It would certainly need an X11 equivalent, and maybe gui libraries. Or maybe even libraries work differently, too. Maybe bash is outdated and something crazy like lua, lisp, or even a hot code reloading compiled language replaces it. (Yes I realize the purpose/usage of bash and those other languages are totally different, but I want to allow OS designs that are so totally different that something crazy like this might make sense)
I realize this question has a huge scope, so go wild with the answers. Any opinions you have about anything could lead me down an interesting rabbit hole as I try learning more about linux.