[TZubiri]

1st of all yes, many people consider not only chroot to be virtualization (of the file system). Yes it is arguable as it is the birth of lightweight virtualization. But you were wrong in saying no one does.

https://papers.freebsd.org/2000/phk-jails/

https://youtu.be/hgN8pCMLI2U?si=CH-Fpyj16bEWDZzc

2nd containers go farther and virtualize network, and other resources.