I would actually disagree here. As long as you need the whole thing available to Node-RED, a JSON file loaded to memory is much easier to work with and avoids the additional complexity of a database.
Only if you need to query or aggregate data would a SQL database be a better bet.
As this is "just" a lookup table referenced directly, the JSON is ideal.
Absolutely, this is much simpler than messing with file read/write's. It just works. I'm using it a lot and gradually migrating any older solutions to this. You can back up the resulting files as well.