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It's a simple fact, the farther the pinion centerline is away from the ring gear centerline, as a percentage, the lower the mechanical efficiency. That's because there is more sliding of surfaces.

These are called hypoid gears. The inventor of the hypoid gear actually worked out the mathematics of the surfaces before building the first one. That flat boggles my mind. Before his invention, those right angle gear drives had the pinion centerline and ring gear centerline intersecting.

The hypoid gearset allowed car manufacturers to lower the driveshaft, thus lower the floor of the car.

Hypoid gearsets mandated the development of Extreme Pressure (EP or GL-5) gear lubes to deal with the sliding surfaces.

R.

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Someone has done their home work
Bonus question; who and where was the Hypoid invented???

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Spicer invented it
EDIT
Maybe I'm wrong but I believe it was Spicer who made
the first ones... but I found this as well

Mr. Trbojevich’s most notable work that brought him international recognition was the invention of the Hypoid gear. First published in 1923, it was a new type of spiral bevel gear employing previously unexploited mathematical techniques. The Hypoid gear is used on the great majority of all cars, trucks and military vehicles today. Together with his invention of the tools and machines necessary for its manufacture, the Hypoid gear became an integral part of the final drive mechanism of automobiles by 1931. Its effect was immediately apparent in that the overall height of rear-drive passenger automobiles was reduced by at least four inches.

But I also read that Packard was putting the Hypoid
gear in their cars in 1918