I don't usually post here, but I agree with Rickey. It sounds like the laws of physics are being repealed. To equalize things, let's assume a GM V8 with a 30 weight oil with an oil temperature of 100C. Under ideal conditions, neglecting heat loss, friction losses, etc, pressure is built due to resistance to flow. The idea here is to maintain an adequate flow rate across the bearings. Again, for the sake of argument, let's assume the engine builds 50 psi of oil pressure at a 3000 rpm cruise. Also for the sake of argument, let's say the pressure relief on the pump is 65 psi, a typical high performance pump. The only resistance to flow is the bearing clearances. Wider clearances mean more flow. Wider clearances also mean lower oil pressure. Since this is a positive displacement pump, the same amount of oil is moved whether the oil pressure is 10 or 60 psi at 3000 rpm. However, at 10 psi, I doubt any oil is getting past the first bearing journal. (All else being equal, I would use a high volume pump in an engine with wider than normal bearing clearances.)
In this case, again with all other things being equal, 50 psi would generally indicate healthy bearings and 10 psi means rebuild time.
As to whether or not there is value to a high volume oil pump, as long as it is not opening the bypass, more oil at a higher pressure will be delivered to the bearings. All else being equal, the bearings will get better lubrication. Even if the pump is in bypass, what is the problem with that? You will still deliver all the oil the engine can flow at 65 psi.
No one rebuilds engines due to high oil pressure at operating temperatures.
Are there advantages to higher/lower viscosity oils? That is a different question.