Engineers who design consumer products work hard to drive the material and production cost down. Cutting a few cents here and there can make the difference between a success and failure. They will not use this part to replace a less expensive one. There is no up side.
The money paid to the manufacturer is only some of the cost of fitting the component. In this case, the cost is quite small and the difference between the 74AUP1G97 and other single-gate ICs is even less, about 1 or 2 cents.
Production costs include getting the right component to manufacture at the right time, and having fewer different components reduces that cost.
Even items that have large production runs end up with extra components for unused functions, or for extra safety factor that may or may not be worth having.
There is also development time savings to be considered. If the engineers can reuse a component for which they know its characteristics and availability, time is saved.
Two examples of extra stuff spring to mind:-
1) High frequency boards are often full of capacitors, have a full ground plane and have lots of through-board connections to make sure the ground is good. Most of those boards will not need every capacitor and every hole but it is usually cheaper to make it like that than to spend time optimising to save a few cents per item.
2) I had a car that had a 4 cylinder engine and one exhaust pipe, but that model was also sold with a V6 and an exhaust either side. Mine had a heat shield on both sides of the engine bay, as they obviously decided it was cheaper to fit the full heat shield on everything than to mix and match.