2015 Macbook Pro 15" loose keyboard?

Then return it to the Apple Store where it was purchased. Bring your receipt and all packaging. Erase the drive and reset it to the default you received: What to do before selling or giving away your post-Snow Leopard Mac. Explain your concern as relates to the other machines' keyboards in the store and ask for a replacement. If you are within 14 days from the date of purchase there are no questions asked regarding a replacement or money back. I suggest you do this with the store manager. Be polite. You will need to make an appointment at the Apple Genius Bar in advance.

Comparing a 4 or 5-year-old keyboard to your newer one is hardly evidence of anything. If you purchased this from Apple then return it for a replace or return. If you purchased it used then you can see about getting the keyboard replaced provided there is actually a problem. Simply not liking the "feel" of the keyboard isn't going to move anyone to anything. It's just the way it is.