Right, and 99.9% don't shoot that much. 1500 rounds isn't a magic number for barrel wear either, lot's of factors there.
You are correct in shooting cadence and it's effect on barrel (throat) wear. So are a lot of other factors.
1,500 is being extremely generous in many cartridges though...especially the moment their run hard for a day or two (which is impossible to tell without inspection with a borescope). It isn't uncommon for many of those cartridges to burn .007 or more of throat every 100 rounds without being pushed hard. As a lover of all things .22-250, I am unfortunately very aware of this.
^ Now, accuracy expectations depend on the owner. If my rifle goes from .5 MOA to 1.5 MOA and I lose 75-100 FPS, or I start throwing uncalled fliers, I'm trashing the barrel...hence my original post about factoring a barrel swap if I buy a rifle chambered in a cartridge known to be a "barrel burner".
^ Therefore barrel life is subjective as well. For someone who is happy with MOA + performance, or doesn't mind setting the barrel back, then maybe they'll get another 500 rounds out of a barrel than I will.