Imagine 1,000s of helm charts. Your only abstraction tools are an umbrella chart or a library chart. There isn't much more in helm.

I liked KRO's model a lot but stringly typed text templating at the scale of thousands of services doesn't work, it's not fun when you need to make a change. I kinda like jsonnet plus the google cli i forget the name of right now, and the abstraction the Grafana folks did too but ultimately i decided to roll my own thing and leaned heavily into type safety for this. It's ideal. With any luck i can open source it. There's a few similar ideas floating around now - Scala Yaga is one.