Why do real estate agencies list square footage of homes when selling them?

If it is the buyers responsibility to make sure square footage is correct, why even list it?Since the realtor can advertise lies and not be held accountable, why list it? If a house is listed as 3000sq ft with 3bd and 3 baths and is really only 2500sq ft with 2bd and 2 baths- why can the realtor lie. If the buyer must double check the listing, then why list anything but the price of the house?