Jovan Popovic shows how to use FOR JSON PATH to output rows in a table to JSON line-delimited format:
Although this is not a valid JSON format, many system use it to exchange data.
One advantage of line-delimited JSON format compared to the standard JSON is the fact that you can append new JSON objects at the end of the file without removing closing array bracket as in the standard JSON.
This might be a niche use case, but I’m sure that in this post-XML-all-the-things era, this is more common than you might first expect.