The Queen Elizabeth class carriers are 920 feet long, 230 feet wide and displace 70,600 tonnes ... :-)
Most people don't realise they are built that big as a simple result of Newtonian mechanics. Assuming conventional take-off, the aircraft has to reach a certain take-off speed and there is a maximum force you can impart to the airframe before it breaks. That determines the length of the flight deck and everything else follows.
Andy