For one, I can do away with all of the text parsing that is prone to breakage in case a tool changes their output somewhat (or god help me - tools that can't handle unicode properly).
The power of bash actually comes from the GNU coreutils and other userland software. It has almost very little to with bash.
Try out bash on a busybox and feel the crippled effect.
So you mean PS as a scripting language, not as a shell, is superior. That's not a surprise, since it's newer and designed to do away with many annoyances of Bash. As a shell, however, it is sadly just slightly more usable as the REPL of, e.g., Python.
The power of bash actually comes from the GNU coreutils and other userland software. It has almost very little to with bash.
Try out bash on a busybox and feel the crippled effect.