In the original Unix implementations, /usr was where the home directories of the users were placed (that is to say, /usr/someone was then the directory now known as /home/someone).
It still had /usr/bin and /usr/sbin in it and scripts, muscle memory and general inertia to contend with. Yes of course it should have gone away, perl should have been at v6 and python at v3 years ago.
I'm off to saddle up my piggie squadron for a flypast.
https://www.bell-labs.com/usr/dmr/www/notes.html
See also, from:
https://www.tldp.org/LDP/Linux-Filesystem-Hierarchy/html/usr...
In the original Unix implementations, /usr was where the home directories of the users were placed (that is to say, /usr/someone was then the directory now known as /home/someone).