it's always preferable to store a json encoded representation
That's just the format du jour. Ten years ago it would have been "store an XML encoded representation" and ten years before that it would have been some delimited representation. Tomorrow it may be yaml or something even more hideous.
Blobs in the DB can make sense in some situations but they should really be blobs: images, or other binary/raw data. But beyond a certain size it's almost always easier to manage things like these in a filesystem and just store a pointer (filename) in the DB.
That's just the format du jour. Ten years ago it would have been "store an XML encoded representation" and ten years before that it would have been some delimited representation. Tomorrow it may be yaml or something even more hideous.
Blobs in the DB can make sense in some situations but they should really be blobs: images, or other binary/raw data. But beyond a certain size it's almost always easier to manage things like these in a filesystem and just store a pointer (filename) in the DB.