The tl;dr is that inheritance is bad in config, whether it be from OOP or layering yaml files like Helm. The reason being that it is hard to understand where a value is coming from and where one must make an edit to correct it in high-stress SRE situations like downtime. Marcel worked on both major config languages at Google, and iirc Starlark is based on GCL ideas

The Logic of CUE is a great read: https://cuelang.org/docs/concept/the-logic-of-cue/