Well, I heard very sensitive people saying that these are actually great, because without these labels, cross-contamination from the factory happens and they get reactions for food that naturally shouln't contain any gluten. I'm not sure how common it is, but I heard it happens.

It always seemed like silly marketing until your kid gets Alfa-gal or you start cooking for people with allergies. The amount of stuff that has additives made from mammals, wheat, shellfish, egg, etc is really surprising. Processed in a factory/machine that also produces nuts, etc can be enough to kill some people. If they can and will say X free instead of saying everything “may contain X” that is a wonderful thing.

Flavored chips can often have gluten in them in the form of "Natural Flavorings" or "Carmel Coloring" which can contain gluten unless the product is labeled gluten-free. It's rather astonishing how many foods can end up with gluten in them because of those two ingredient items.

There was a lawsuit in the Netherlands when a lollypop maker marketed their candy as "energy for your brain". Thankfully, while it's technically correct, that was deemed not actually legal.

You can, however, still brand your salt as vegan and your banana as gluten free.