> The world desperately needs a replacement for YAML.
The world desperately needs support for YAML 1.2, which solves the problems the article addresses fairly completely (largely in the “default” Core schema[0], but more completely with the support for schemas in general), plus a bunch of others, and has for more than a decade. But YAML 1.2 libraries aren’t available for most languages.
[0] not actually an official default, but reflects a cleanup of the YAML 1.1 behavior without optional types, so its defaultish. Back when it looked like YAML 1.3 might happen in some reasonably-near future, it was actually indicated by team members that the JSON Schema for YAML (not to be confused with the JSON Schema spec) would be the explicit default YAML Schema in 1.3, which has a lot to recommend it.