You appear to be talking about road cars.
Road bikes tend to use rims a similar width to the tyre, and by running them at high pressures maintain the carcass shape.
Off road bikes use 'balloon' tyres to allow the tread pattern to conform to the contours of the terrain on which it is running, thereby increacing traction, and spreading the weight over the greatest surface area possible.
Off road vehicles also use this principle.
Tyre design for bikes is a big industry, and some very clever people have looked at it. Many of the comapnies that make our bike tyres are big into other areas of the tyre industry. Hardly a cottage industry!
It is silly to compare car tyre design and bike tyre design, they preform very very differing functions. A car tyre does not have to work through a 90 degree axis of camber angle for a start!
Motocross bikes use narrower rims than the tyre width to give a rounded profile and to put the largest number of tread blocks on the dirt as the bike leans over.
If you want to try your idea out then I suggest some Halo Trials rims, and a 2" tyre and see if there is an improvment, just because the majority say it is right don't make it so.
Somerset, like 'Heartbeat' with newer cars!
Retro MTB: 1992 Cannondale M1000 Deore XT M730. 1992 Raleigh Dyna Tech Quantum Deore XT.
Retro Road: 1992 Eddy Merckx Corsa Extra Telekom Shimano 6500 Ultegra. 1993 Dyna Tech Ti Campagnolo Athena 8 Ergopower.
Modern: 2004 Wilier scandium Ultegra 6800. 2014 Wilier GTR Dura Ace 9000.