> to merge /sbin with /bin, and /usr/sbin with /usr/bin
It's a bit more drastic than you make it out to be. This would give two valid $PATHS to the same commands. It would make tab-completion slow. It would likely break all kinds of compatibility across the SUS. And it is incredibly arbitrary, no better or worse than eliminating system hierarchy entirely and putting everything in /.
> to merge /sbin with /bin, and /usr/sbin with /usr/bin
It's a bit more drastic than you make it out to be. This would give two valid $PATHS to the same commands. It would make tab-completion slow. It would likely break all kinds of compatibility across the SUS. And it is incredibly arbitrary, no better or worse than eliminating system hierarchy entirely and putting everything in /.