If you're planning to run those as a platform, it sounds like more pain then necessary.
(I use NixOS for personal use.)
The customers were screaming for it. They want a simpla and reliable way to deploy k8s without a team of specialist, and the guarantee to receive security updates for years without having to upgrade to a new version.
You also know, that your issue with that setup might get noticed by someone else using the same and will fix it for you.
You get sane defaults and you get k8s optimized for the os.
I run microk8s at home. Its simple, fast, easy and works.
Not seeing any issue with it.
I've run openstack for a while and... realistically if you run a platform, you need to have people/time to manage it. I understand from conversations about k8s that is not that much different.