If yaml didn’t have anchors and 8 different white space formats, it’d be a great replacement for this kind of thing.

But yaml is a mess, and you’d think you could parse it easily, but you can’t.

I’m a fan of NestedText. It’s no panacea but I’d argue it’s the most well-considered and useful file format for structured data in plain text.
There just needs to be one universal standard that handles everyone’s use cases
Standards

xkcd