What's needed is something that is simple for humans to read and write, has a stable definition, and a clear and unambiguous syntax and mapping to data objects.

What's needed is something that is simple for humans to read and write, has a stable definition, and a clear and unambiguous syntax and mapping to data objects. None of the systems I've seen achieve all those goals at once. YAML, while at first sight a good idea, is irredeemably broken and should be deprecated for further use. JSONC (https://jsonc.org/ https://jsonc.org/) is backwards-compatible with JSON, and a good target for long-term future migration. .INI format works well as a structured subject-predicate-object tuple store for simple use cases. We're probably going to have to live with that indifinitely, until someone comes up with a proposal that is better.