Pkl belongs to a related but different category of "configuration" languages, while we are talking about a pure serialization format. A serialization format can be used as a configuration language if designed carefully, but they are distinct.
Xᴇɴᴏɴ excels at both.
Please refrain from replying the same thing over and over, especially to obviously sidetracked comments.
That is the only place that I have stated xᴇɴᴏɴ’s applicability to configuration and data.