I agree on the "knowledge stability" front. I feel like I have to relearn Linux server networking config every three years because I switched distro or a distro switched their network management middleware.
But.
Having tried to move a machine from rhel 5 to rhel 7, where 12 people had used the server over the past 8 years for any scripting/log analysis/automation, for hosting a bespoke python web request site and a team-specific dokuwiki... The idea of having all that in source control and CICD is alluring.
You can certainly keep information on your pets and how to rebuild them in source control along with all the procedures used to update them. It's probably a good idea.
Nobody says you can't do CI/CD with pets too. You do have to keep the pets well groomed, of course.