1980, PGA Tour began publishing statistics (yes I remember). Dan Pohl led the tour at 274,3 yards. Tour average was 256 and change. That was 38 years ago. 1997, John Daley was the first to average 300 yards per drive. Pohl's leading distance was below the average drive on tour today. I suspect that human evolution and improvements in technique have not improved enough in less than 40 years to account for these changes, although I concede that there are more good athletes attracted to golf and greater emphasis on training. The unaccounted for variable is equipment. A factor not often discussed is the synergy between the longer, more forgiving and livelier drivers and the new balls.
My concern is not for the ordinary club player. But so long as we care about the nature of the challenge presented to professionals and top amateurs this is disturbing in its impact on architecture. The ability to hit accurate long irons used to be a significant factor in separating the good from the great players. Now, the only time one sees a long iron is on very tight driving holes, extremely long par 3's and extraordinarily long par 5's. Additionally, because it is harder to hit these clubs and balls "crooked", players are encouraged to "go after" their shots whereas players of the Nicklaus era and before always talked about swinging within themselves The fact that most par 4's are now a driver and short iron lessens the need to hit the fairway. All of these factors have obsoleted great golf courses, absent ridiculous efforts to "toughen" them which usually destroy the basic strategic concepts that make them great. I think that it also makes the game less interesting, although I concede that is only one man's opinion.
But the biggest impact is that it creates a de facto bifurcation in the game. Realistically, there was always a huge difference between the pros and the rest of us. But because the distance factor was not as great, we could play the same golf courses and the differences in our games were such that the courses worked for both groups. Thus, we could more easily identify with the challenges faced by the pros.
From a GCA perspective, this requires significant additional land to build new courses (or alternatively building courses that make hitting driver too dangerous for the long hitter) and requires the previously mentioned modifications to classic courses when they are used for professional tourneys. Alternatively, the course becomes irrelevant to the pros which is often a rational choice.
Unfortunately, the genie is out of the bottle and I suspect there is little too be done.