There is no precise system to capture the difference between the Giro and the Tour because a thousand variables exist, but numbers can certainly help. So let's look at the main one, the final hourly average: Pogacar finished the Grande Boucle by covering 3,298.6 km at an average of 43.389 km/h. Literally pulverizing the record average previously set by Jonas Vingegaard three years ago at 42.102.

Rewind your memory: practically for just one stage, stage number 3, the peloton eased off the accelerator, for the rest they were going all out from the beginning to the end of every stage and, as often happens, in the toughest stages they went even faster! And this record average was set in a race that proposed 52,500 meters of elevation gain.

Pogacar also holds the record for the fastest hourly average ever at the Giro d'Italia: last year he pedaled at an average of 41.860 km/h in a race of 3,317.5 km with a total elevation of 44,650 meters. The explanation? Different opponents, different motivations, different race.
And it's not hard to understand why the riders arrived in Paris completely exhausted...