Why do Naval Historians not still use the Age of Sail Rating system?

Gun-count labels such as 74 and 80 grouped Age of Sail warships into ratings and gave a concise description of their armament.

Modern gun totals lost much of their value once calibre, shell effects, range, and accuracy determined what a few weapons could achieve.

For a modern warship, its role and principal battery, such as 6-inch or 8-inch cruiser guns, reveal more than a total that mixes many weapon types.

A dramatic total such as 90 guns can mislead when many of those weapons are machine guns with little bearing on a ship-to-ship gunnery duel.