It’s basic functionality dressed up for marketing. It is silly, because you really don’t need a shutter button that often. But the device can do it, so why not? It’s not a selling feature, but it wouldn’t make sense not to include some kind of button function.
It’s like if a car manufacturer got really enthusiastic about how you can recline your seatbacks which lets you take a nap in your car. Like, OK, there are a lot of reasons to have reclining seats, but in practice you rarely need the feature. But to not have it would be even stupider.