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.
YAML 1.2 leaves data types ambiguous, merely making the "Norway problem" optional and at the mercy of the application rather than, in the words of https://yaml.org/type/ (which has not been marked as deprecated), "strongly recommended".
Those schemas aren't part of the core schema, and you may interpret them if you are aiming for full 1.1 compatibility. If you're aiming for 1.1 compatibility, then you accept the Norway problem.
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.