Gonna date myself but, for ~80% of configuration needs good old INI never let me down. Named sections of name value pairs with string and number data types (maybe bools too. do not recall). et voilà!
Honestly if the config layout fits in ini, there's no reason not to use it.
YAML is great for human-readable config, and there are footguns.
XML is terrible for human-readable config. JSON is not great for human-readable config. TOML is okay for human-readable config.
The problem is there's no clean way to abstract strings, bools, lists, objects, trees, etc. into a human-readable configuration syntax that does not have a footgun.
> The problem is there's no clean way to abstract strings, bools, lists, objects, trees, etc. into a human-readable configuration syntax that does not have a footgun.
My favorite take on this by far is that any types beyond string, list, and dict don't belong in the format at all, and should be left to the ingesting code. I started on the path thanks to StrictYAML and found a home with NestedText.
INI is great for some flatter types of configuration (and I still use it too), but once you need a little bit of nesting, or lists, INI starts to get cumbersome.
YAML is great for human-readable config, and there are footguns.
XML is terrible for human-readable config. JSON is not great for human-readable config. TOML is okay for human-readable config.
The problem is there's no clean way to abstract strings, bools, lists, objects, trees, etc. into a human-readable configuration syntax that does not have a footgun.