Have you heard of or explored https://github.com/aws/constructs (related: https://github.com/aws/jsii and https://github.com/aws/aws-cdk)?

This is what CDK uses for declarative modeling, but gives the opportunity to use languages/tooling that most devs are already familiar with. CDK8s already uses it as a replacement for yaml (technically, the yaml becomes an implementation detail rather than actually replaced)