Lets look at a specific example. Take Kubernetes: everything is yaml, with complete schemas, all the way down. From your perspective this is configuration utopia, right? Meanwhile back in reality k8s is the poster child of "yaml hell". From the day it was released, people took one look at it, gave it a giant NOPE and instantly spawned half a dozen templating languages. The most popular of these is helm, which has a terrible, no good, very bad design: full of potential injection attacks from purely textual string substitution, manually specified indentation to embed parameterized blocks, virtually no intermediate validation, no way to validate unused features, etc etc

Compare to dhall which publishes a complete set of dhall-k8s schema mappings which enables you to factor out any design you want down to as few configuration variables as you like, while validating the configuration generators themselves at design time. https://github.com/dhall-lang/dhall-kubernetes#more-modular-...