I don't know to what extent you got molested by the prophets of immutable distros yet, but I can only recommend to join the cult. Install Fedora IoT (or CoreOS) and simply know that you'll get a working container host (powered by podman) with every update. The whole discussion about which distro might survive whatever massacre the respective package manager commits next becomes superflous: You simply get the next image that was built upstream solely to serve containers. The whole package-udpating-shengiangs is done by other people for you, you only collect the sweet result. The only "downside" is that one has to become familiar with containers, but since you run docker already that should work out. Also for stuff like tinkering with the latest tools, just put those in a distrobox. That way they are indipendent from your solid container host, and you can mess them up in whatevery way you fancy and dispose them without any traces left behind.
Edit: To give one more example why this is awesome: It wouldn't even matter which one you install, you can just rebase to the other (IoT lives in the fedora-iot remote. silverblue, coreos and the others in the fedora remote. Just for anybody who might be confused by only looking at ostree remote refs fedora)
In my experience, not pushing it makes them want to try it themselves at some point. I guess you need to take care of their computer frequently enough, and are probably annoyed by Windows shitting its pants every time again. Don't make any drama out of it, just point out how ridiculous it is that Microsoft cannot manage to build something that allows running two simple programs without breaking or nagging the user so often. They know that you use something else with which you're happy with, and at some point they will become curious and ask wheter they can have it too. At that point do not promise much, say that it works a lot better but is also a lot different and sometimes a bit quirky. Do not rush it now, let them simmer in their curiousity. At a fitting occasion tell them very briefly about foss and how it is not a closed thing pushed by a corporation onto individuals to funnel data. When they ask if they can try it, tell them they can but it takes a bit of getting used to. Buy a new SSD, and safely store the previous storage in a anti static bag, exclaiming that everything is on there and cannot get lost due to linux. Set everything up with a dead easy DE, give clear tour of how stuff works. With this tactic, they want to get it to work by themselves, and are prepared to learn that some things work differently. It becomes an adventure that is totally revertable if it doesn't work out. In contrast to when you want to force the change and they use everything as a reason to be unhappy about it.