Richard Choi,
Years ago or rather decades ago, before 46 inch shafts with oversized tennis rackets affixed, they conducted that study.
I believe the ideal height was in the 5' 10" range.
There's something to be said for a compact swing.
Being 6' 8" isn't an advantage if you can't control and produce a precise swing.
And, you can't swing at tremendous speed if the increased speed produces mis-hits.
To illustrate the point, put today's 3-wood in the hands of the biggest strongest athlete you know and see how he fares as he tries to drive the ball six miles. He'll run out of ammo before he hits the back nine.
The huge club head, coupled with lighter, stronger shafts has allowed golfers to "swing away" without fear.
When the USGA caved in and allowed the larger size club head it advanced the emphasis on distance.
I used to play with Evan "big cat" Williams, a very nice fellow and one of the first "long" drivers of the golf ball.
With the "olde" equipment, it was one thing to hit the ball long, it was quite another to control it.
Today's equipment has solved the latter problem to a great degree.