RHEL and other extremly long term support distros that have a significant user base because they hold back a lot of software features, network protocol features and moves to new dependencies that are required to work on the oldest and the newest supported distro for any given upstream software project.
Also, any time I have to learn something about a quirk in a version of software in use there it is basically wasted life time because the knowledge is already outdated by the time I obtain it.