Adam,
I think it's universally or almost universally acknowledged that a course has to tighten up it's fairways when conducting a major national championship for the greatest golfers in the world.
Today at around 4:00 I stopped by my club to hit balls.
The Pro, preparing for the Met Open, was hitting balls next to me.
He was using a high tech device, I believe it's called "foresight".
It's a launch monitor.
I was watching him hit 8-irons.
He was leaving them out to the right, cutting them slightly, his swing path was Outside-In but his club face was open.
I told him that his face was open at address.
I then put rods down, a red one at his target and a blue one 5 inches from the ball at a 90 degree angle to the target rod.
When I had him align his club with the blue rod, he said he thought his face was closed, but he began hitting his 8-iron and his flight immediately improved, as did his ball speed and distance. He then informed me that his usual 8-iron distance was 165 yards.
He then told me that on the 3rd hole at Plainfield, at 180 yards, that Sergio Garcia was hitting 8-iron.
8-iron from 180.
He then began hitting his 3-wood/metal.........270+
We also know that today's ball flies straighter.
So, how can Merion, built circa 1912, provide a challenge against the modern golfer without altering the golf course ?