True, though one may turn that around to say Cue's scope is too large while Jsonnet's is more "pure" while still enabling the larger scope.
Schema that describes data is itself just data and Jsonnet can describe both. While the various Jsonnet compilers do not "know" about any specific meta-schema in which to express schema nor of course any way to apply that schema to data for validation, one can create such systems with Jsonnet as the language and its compilers as a component.
True, CUE has quite the inspirational scope right in the name. It is actually what draws me to the language. I also like the theoretical foundations in being turing-incomplete. Functions and computation make configuration harder to understand and reason about.
Schema that describes data is itself just data and Jsonnet can describe both. While the various Jsonnet compilers do not "know" about any specific meta-schema in which to express schema nor of course any way to apply that schema to data for validation, one can create such systems with Jsonnet as the language and its compilers as a component.