I don’t usually keep OEM tires on my vehicles very long since I find them lacking. For trucks, it’s usually traction and toughness they are lacking. In any case, I’ve noticed huge load rating differences for tires even for SUVs. Sure, it costs money, but you can almost always find a better tire than stock. For sedans, it’s ride quality and noise. For sports cars, back to traction and ride quality. Of course, you can also find worse tires than OEM.
What’s the reference source for the 80% number?