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$pid is empty, so you don't get any profile info, but that doesn't matter because you don't do anything with it anyway.
You set $_data to be an empty array, but that doesn't matter because you don't do anything with it either.
You don't save anything (which is why the datastore is empty, although it would still be empty if you did save as your $_data array is set to be empty).
Then you set the form notice to notify you of success, which is why you see the success message.
So you didn't do anything apart from setting a success message, which is why you see that.