I guess it does the PATH hacking based on whether the system is GNU or not so that it can get `realpath`/`readlink -f`-like behavior even on systems that don't natively have that because they include *BSD coreutils.
That might not behave as expected (and is unnecessary) on my macOS systems, either, since I like to keep GNU coreutils (with no `g` prefixes on the executable names) on my PATH there (heresy, I know).
It's also noticeably slower, to the point that there's a bit of jitter as I type.
It's pretty cool, though. If it's any better after I patch the readlink PATH hacking out, maybe I'll configure it for bash on my systems.
That's weird. Fish has all of the GNU readline shortcuts OOTB and has for as long as I can remember