Why longer modern warships do not carry less firepower

Why did warships become longer while appearing to carry fewer weapons?

Their weapons deliver greater firepower and range, while computers and support facilities add to the space needed to use them.

Longer modern warships can carry fewer visible gun mountings while delivering much greater firepower. A Type 23 frigate's single 4.5-inch gun is used in a counterfactual comparison with the fleets at Trafalgar: its range would let it attack without entering the sailing ships' gun range. Modern ships also need computers and support facilities to control their weapons, especially at long distances. Hull size therefore reflects the equipment needed to use the weapons as well as the weapons themselves.