Why useful carrier size grows across the jet age

What carrier displacement best suits a country the size of Britain or France?

The useful size rises with the era: modern aircraft, sensors, support systems, and crew needs make a roughly Queen Elizabeth-sized carrier appropriate today.

The suggested displacement rises from roughly 50,000 tons in the 1950s to 60,000 in the 1960s and 1970s, then about 70,000 in the contemporary era. Larger aircraft and command-and-control equipment require more space, as do support systems and improved living conditions. The resulting growth is tied to operating requirements rather than size for its own sake.