WordPress galleries do not give you the option to link any of the images to an attachment page or media file. I also didn't get to select how I wanted my galleries to appear in columns or the size of the images that I wanted to use.
Also when I created the gallery, I had to hold my key down (shift/control/command) to select multiple images. It should be automatic that if I clicked the block to create a gallery there would be multiple images – so why do I need to do this? Some users get confused with the whole shift/control/command execution to select multiple images.