If you mean how they work, like command line arguments and such (and not just speed), that's because macOS is based on BSD and thus using the BSD and not GNU versions. That's not really a "not right" thing, it's just different, and would be the same if you used any other BSD like OpenBSD, FreeBSD, etc.
I used GNU ones without the `g` prefix for a year or two and never ran into trouble because of it.
Take the example of 'tar' that slowly evolved and some time even changed its default behaviour. e.g. what to do when untaring a folder but there's already a symlink with the same name as the folder, do you erase the symlink and create a folder or do you untar the folder in the symlink? Between centos 5 and 7 this changed... Causing me some amount of pain.
hostname stopped supporting '_' in host names. Could have raised a warning, have added a '-pedantic' option but no.
hostname stopped assigning the permanent host name with the 'hostname myhostname' command and now you need to use hostnamectl. Could have left the 'old' feature and make hostnamectl whine instead, but no.
ifconfig the deprecated tool subtly changed the order of fields too and now the MAC address is not in the same place as before, breaking scripts that trusted that not to change.
df changed its syntax, adding or removing a new-line some time ago.
Yeah thinking back we shouldn't have used the standard tools and expected them not to change.
So, now, whenever I see in code review some bash person using 'standard' tools to get info that could be gathered through procfs or sysfs, I instead ask they use procfs, sysfs or ioctls and be done with it.
Take the evolution in /proc/meminfo that changed the meaning of some of the lines there over time (WTF?), whilst adding others (which was fine, expected, etc.). Of course I want now to include IO cache (that will be reclaimed if I ever needed to malloc) in my system's free memory indicator! Heh you can still get back the old value with this formula, what are whining about?
This 2 year old HN post shows the performance difference between Gnu grep and BSD grep on Macos:
sed 4.8 - 15 Jan 2021
awk 5.1.1 - 28 Oct 2021
grep 3.7 - 14 Aug 2021
What am I missing here?