Autoscaling is honestly a minor thing (I have yet to use Autoscaling other than cluster autoscaling since 2016) and autotuning... what autotuning are you talking about? The binpacking support?
Also, I do wonder what "elegant way" would be, considering that k8s is a very elegant system (once you notice that YAML is just one of the serialization formats to make it easier for raw API access by humans).
No, the complexity of Kybernetes is mostly in its auto-tuning and auto-scaling features. That's the stuff that needs to be re-engineered from the ground up in an elegant way. If history is any guide, we'll probably end up with some variant of it in systemd sooner rather than later.