This is the best explanation of crankshaft to bearing fuction I've heard by far. Yes the crankshaft does ride on a wedge of oil a film controlled by clearence and a direct derevative of oil pressure. Without that film or wedge which ever the term one likes to use, the engine would experience detrimental issues. On most new engines these clearences are as low as .0001-.00013. To me that is still too tight which in the end gives higher temps greater chances for the oil film to deteriorate, which in turn gives more metal to metal contact. Fact the manufactures have gone to a thinner oil to improve their cafe standards. Giving an engine that will last till their warranty under normal use. But fall short if used as we most use our cars, to have fun with. I would love to see a mechanical gauge being used. When I had my ZO6 it had an oil temp reading as the oil temps increased the oil press dropped. Im willing to bet thats also happening to some extent with the 5.0. Most guys switched to better oils to help relieve this problem, it didn't solve it completetly but did reduce it.
Oil does thins out when it hot. Some manufactures run oil temp hotter than coolant by 30 degs. Why because it pumps easier less power lost. Oil film yes crank still doesn't exactly ride on cushion of oil. Everytime cyl fires that oil is pushed out of the bearing. If you crank oil pressure really high it will also wash bearings out make them flake and come apart. Oil is coolant for bearing taking heat away so bearings won't seize. Like I said before how does engine that's never shut off wear out? According to some everything rides on wedge of oil so in theory it should never wear out