Pkl is a hell of a lot easier to work with. Compare this pkl code:

host: String
port: UInt16(this > 1000)

To the equivalent in json:

{
  "$schema": "http://example.org/my-project/schema#",
  "type": "object",
  "properties": {
    "host": {
      "type": "string"
    },
    "port": {
      "type": "number",
      "minimum": 1000,
      "exclusiveMinimum": true
    }
  },
  "required": ["host", "port"]
}