Whenever I ask myself "should I use YAML?" I answer myself "Norway".

> I feel like YAML is a spiritual successor to the .ini, since it shares a notable ideal of simple human readability/writability.

It doesn't feel that way to me: it's neither simple to read nor to write. I suppose that that's a builtin problem due to tree representation, which is something that INI files were never expected to represent.

TBH, I actually prefer the various tree representation workarounds used by INI files: using whitespace to indicate child nodes stops being readable once you have more than a screenful of children in a node.

Given how YAML does magic and sometimes accidental type conversions of potentially nested objects, I think TOML is the well-defined sucessor to .ini

YAML is readable? No way as there are too many ways to do the same thing and nested structures are unclear to the non trained eye (what is a list? What is nested?), let alone indentation in large files is an issue especially with the default 2 space unreadable standard so many people adhere to.

YAML simple? It's sepc is larger than XML... Parsing of numbers and strings is ambiguous, leading zeros are not strings but octal (implicit conversion...). List as keys? Oh ffs, and you said readable. And do not get me started about "Yes" being a boolean, reminds me of the MS Access localizations which had other decimal values for true and [local variant of true] (1 vs -1).

Writable? Even worse. I think I have never been able to write a YAML file without errors. But that might just be me, XML is fine though while unreadable.

I think GRON[1] would fit the bill better

[1] https://github.com/tomnomnom/gron