"Let the unit die and just create new ones every few years" is a brilliant solution to many issues in complex systems. Practically all software created by humans behaves the same way - want a new version of your browser or a new major version of your OS kernel or whatever else - you have to restart them.
"The creatures outside looked from DNA to k8s YAML, and from k8s YAML to DNA, and from DNA to k8s YAML again; but already it was impossible to say which was which."
Death isn’t a solution to maintenance issues, there are some organisms including animals that live many hundreds of years and possibly indefinitely. The reason seems to be to increase the rate of iterations, to keep up the pace of adaptation and evolution.
It's more of a "sleep mode". There are still a lot of wakeups, and cron jobs running clean up of temporary files, cache management and backup routines. Background services still run.
Poor comparison - DNA is compiled assembly language code. It is meant to be spaghetti to save space and reuse proteins for multiple functions. In that regard it’s the most efficient compiler in the universe.
DNA is the worst spaghetti code imaginable.
The design is such a hack, that it's easier to let the unit die and just create new ones every few years.