If you're interested, Red Hat has a very thorough guide on how to achieve this with free and open-source software. While you have to run VMs rather than containers, it's much more robust. [2] There are proprietary options too.
And then, there's also the good old fallback method that k8s uses: just divert traffic to healthy nodes and fire up a replacement. There are many frameworks for that simple model, and there's no reason to pretend that it's done exclusively with handcrafted "buggy shell scripts", nor to pretend that "buggy shell scripts" are inherently worse than "incorrect YAML configs that confused k8s and killed everything in our cluster" (see OP for a compendium of such incidents).
[0; PDF] https://www.usenix.org/legacy/event/nsdi05/tech/full_papers/...
[1] https://en.wikipedia.org/wiki/Live_migration
[2] https://access.redhat.com/documentation/en-us/red_hat_enterp...
You say things are possible and provide links to building blocks but haven’t said how you do it end to end