You two guys are arguing about two different things.
I run a cabinet shop, so I think I know a little bit about the subject.
Some woods, like longleaf pine, indeed are harder when they are "old growth" and are 200 to 500 years old. Slow growth gives tight rings, as in maybe 6 growth rings per inch.
Other woods don't live long enough to be considered old growth by the industry. Many trees grow fast and die early.
Do you know where we get most of our maple from? Maple trees get old and can't produce enough valuable sap anymore, so they are cut down and replaced with younger trees.
People love to hear that their maple cabinets were made with sustainably proeduced hardwood.