I share Marcel's view, a DSL is the ideal position on the configuration complexity clock. CUE in particular is ideal for configuration because of how it handles unification.
These comments in particular reminded me of Marcel's video linked at the bottom of that article, where he talks about the history of CUE in the context of configuration languages at Google: https://www.youtube.com/watch?v=jSRXobu1jHk
> Many general purpose languages support type checking, but few support constraints and validation of data. We must write our own validation logic which often means validation happens haphazardly, if at all.
Python with z3 and some AST magic can support constraint validation.
In fact, type checking can be seen as a form of that. I have a fork of typpete, a z3 based type checker from 3 years ago that should still work.
Is gcl great? No. Cue and dhal have better semantics. Do some people abuse it? Sure, but still much better than helm templating.