Imagine "where" on the cam core the lobe is. A good cam grinder can put that lobe anywhere on that core he wants it. In other words, he can move the lobe so that, even though he's ground some off, it will lift the valve more than it did before. Of course, a lot of times an engine will require longer pushrods.
Ahhh, now the Carpenter/ Drywall guy digs it! Thanks Brother! Basically, like I Can, AND HAVE, literally, Raised a Roof, it still has to have " Legs"! But...I just still caint get it.. ain't Max Lift the pointy, narrow ( like my head..) of the lobe?