Until you have a large amount of data & need either random access or to work on multiple full columns at once. Duplicated keys names mean it's very easy for dat

Until you have a large amount of data & need either random access or to work on multiple full columns at once. Duplicated keys names mean it's very easy for data in jsonlines format to be orders of magnitude larger than the same data as CSV, which is incredibly annoying if your processing for it isn't amenable to streaming.