A lot depends on which shop/cafe the bag is from.
My daughter gets hers from the same local independent baker where she has bought excellent bakd goods in the past. She gets a carrier bag full of various kinds of bread, croissants, buns, etc, which are genuinely surplus stock made that day and unsold.
I got a bag from Costa which contained two toasted sandwiches - one had bare cheese, the other baked beans and neither was exactly well-filled - plus an "empire biscuit" and a square of very plain cake. All of it was very dry. I haven't tried since.