Corrected to sea level would be better way of saying it. The normal pressure lapse rate down low (say sea level to 10,000 feet) is about 100 for every .1 of an inch of Hg. So on a standard day the actual pressure in New Orleans is 29.92 and in Denver it'll be about 24.32. The Met people in Denver have a correction factor they add to the actual pressure to bring it up to 29.92. We could use the local pressure and everything would be QFE.

Believe it or not, the world does not revolve around pilots. The weather wizards use pressure to figure out where fronts are and what's going to happen. If everyone just used their local pressure uncorrected for altitude, drawing isobars on a weather map would be useless.