That does not follow. JSON formatted data remains JSON no matter if you use it incorrectly. This happens all the time in the real world - applications unknowi

That does not follow. JSON formatted data remains JSON no matter if you use it incorrectly. This happens all the time in the real world - applications unknowingly rely on undefined (but generally true) behavior. If you e.g. need to integrate with a legacy application where you're not completely sure how it handles JSON, then it's likely better to use plain text JSON. You may take the risk as well, but then good luck explaining that those devs 10 years out of the company are responsible for the breakage happening after you've converted JSON to JSONB. In some cases, insisting on ignoring the key order is too expensive luxury, since it basically forces you to parse the whole document first and only then process it. In case you have huge documents, you have to stream-read and this often implies relying on a particular key order (which isn't a problem since those same huge documents will likely be stream-written with a particular order too).