Piping programs together is almost always going to use significantly more resources than one program doing it all. More code doesn’t necessarily imply more resource usage.

Plan 9 is not an answer to every problem, but it's just impressive how much it can do with so little code.

I don’t want to be all around negative about plan 9, but I don’t see it as really solving any interesting problems. Indeed it is far easier to write slim, elegant systems when forgoing feature parity and/or competitive performance.