It looks like they're aware of that ... it's probably fine -- not ideal, but fine
If users didn't care about what the blob format was, there wouldn't be JSON support in the first place! You would have started with something like JSONB
Also SQLite3 will have to remain backwards compatible with its JSONB forever, which means it's stable, which means there will be users who will feel comfortable using the raw JSONB from SQLite3.
https://www.hyrumslaw.com/
It looks like they're aware of that ... it's probably fine -- not ideal, but fine
If users didn't care about what the blob format was, there wouldn't be JSON support in the first place! You would have started with something like JSONB