I don't know what SQLite does, but in JS the order is actually defined. JS is not Java, object is not HashMap, if anything, it's closer to LinkedHashMap, but even that is not correct because there are numeric slots which always go first.
https://tc39.es/ecma262/#sec-ordinaryownpropertykeys
Defined yes, but still arbitrary and may not be consistent between JSON values of the same schema, as per the document you linked to:
> in ascending chronological order of property creation
Also, while JSON came from JS sort-of, it is, for better or worse (better than XML!) a standard apart from JS with its own definitions and used in many other contexts. JSON as specified does not have a prescribed order for properties, so it is not safe to assume one. JS may generally impose a particular order, but other things may not when [re]creating a JSON string from their internal format (JSONB in this case), so by assuming a particular order will be preserved you would be relying on a behaviour that is undefined in the context of JSON.
Yes, I know, the point was not to say that it's safe to depend on this universally, but rather why it's safe in JS and why it's not elsewhere -> other languages use hash maps simply because authors were either lazy or unaware of the original behaviour. (which sucks, in my opinion, but nobody can fix it now)
> other languages use hash maps simply because authors were either lazy or unaware
Because it is idiomatic in that language, and you often don't need the higher overhead of tracking insertion order.
Before Python 3.7, json.loads used dict (undefined order) and you needed to explicitly need to override the load calls with the kwarg `object_pairs_hook=collections.OrderedDict` to accept ordered dictionaries.
Since Python 3.7 all `dict`s are effectively `collections.OrderedDict` because people now expect this kind of inefficient default behavior everywhere. ¯\_(ツ)_/¯
