30-ish years of using ifconfig. I agree with you. So many changes in such a small amount of time in the last two Red Hat releases.
Just as an aside, macOS *is* UNIX as validated by OpenGroup, the current owners of the UNIX brand and standardization outlines. Linux is "UNIX like" because no single distro has ever approached OpenGroup to certify their distro as an official UNIX.
Also, FreeBSD, OpenBSD and NetBSD are not currently "UNIX" either, even though they *are* BSD. The reasons are the same for Linux. The certification process through OpenGroup is expensive. The open distributions just don't see the point in putting money toward a brand badge to keep up with the likes of AIX.
The information for the price of being UNIX can be found here: