So? They live in the same solution domain for the same problem.
Moreover, Dhall can generate (typechecked) YAML and JSON.
Maybe you'll benefit from the added abstraction; I see the value in having "typed" configs that are semi-scriptable but not turing complete. But it's in no way a "replacement".
If that was in fact all you had done, it would not be worth it. But it might remove a ton of boilerplate from your YAML.
I mean what's the role of configuration? is so that installer can tune or match environments. if configuration becomes as hard as your program to understand then installation won't ever scale
Sorry I don't get it. Why not? Because your favorite languages do not support it?