This is why I started to craft my own format: BCL, https://github.com/wkhere/bcl

Will not immediately help in all cases of YAML usages, but at least can be a cooler way of defining resources in a Terraform-like style. In fact, it's already helpful as a replacement for HCL in one internal project, that was a final motivation to hack it.

In a bigger picture, I have no idea how to help with YAML omnipresence in Kubernetes. More than a half of my problems at a $daily_job is how crude is consolidating a final Helm chart from different sources. I am not saying that Helm would be inherently a bad tool or my company has chosen pretty bad way of using it - I guess everyone is doing their best considering the ciscumstances. But manipulating textual templates with semantic whitespaces is just too error prone, and the detection of errors happens too late. I dare to say - Kubernetes would do much better with custom format based on a C-like syntax, instead if trying to prove how cool YAML is, especially when it isn't.

Have you seen ucl? https://github.com/vstakhov/libucl

It seems very similar.