Sticking to a scripting language with a strong standard library is way better.
Any unix system can get Ruby/Python and read/write YAML/JSON immediately without caring too much about versions.
Of course in today's upside down world most developers seem to only know JS, so it would at least be "familiar". Still a bad choice in my view.
The way this industry is going, give it a few years and we'll have React-Kubernetes for generating templates. And I wish I was joking.
So, to clarify, for JSON JS is definitely not the worse option. For me though, even for JSON, you have much better options.