I've run Fram filters and the cheapest oil I could find with zero problems.
But my current engine makes 3X the power and a fraction of the emission of my 95 Nissan. What worked 5 or 10 years ago does not apply.
There is no way to prove what will work best in my engine. Synthetic oil could help, do nothing, or even damage my engine. It may be 5-6 years before anything is known how oil selection affects the +05 2UZ-FE engine.
No other engine test/research/study apply. It is hard to comprehend how unique engines are today. Starting with the basic materials, my engine has nothing in common with a crown vic, other than 8 cylinders.
Auto manufactures are trying to reduce emission, increase power, and increase MPG. They have big incentives, just an example
CAFE.
Toyota could have made a design decision to help their bottom line, and not you. But you won't find out until it is too late. (and engineers don't make all the decisions

).
If the Toyota powertrain is so good, why only the 5/60k warranty?
Some of the Emission Coverage is longer than the powertrain. Kind of scary. Toyota won't guarantee your engine will last 61k, but they'll replace a bad catalytic converter at 80k.
Toyota feels burning quart of oil every 1500 miles acceptable. Do you? I see too many 'engine rebuild' threads on other forums. And it is not just Toyota, but all manufactures.
I made a decision to put (what I believe is the best) oil in my engine for the long haul. Only time will tell. Not arguing on the internet.