It's 9:30 pm in Scotland and I am pretty jet lagged after a long day of work, so I can't answer you fully, but basically, I don't understand why you care what the winning score is in a tournament, or why I am supposed to care, since I don't build golf courses for professional tournaments?
Thick rough and trees never "worked fine", for anybody apart from very good players. For the other 90% it was an ordeal.
And when the hell has golf architecture NOT encouraged players to hit the ball further? Length with a reasonable amount of accuracy was just as important to Bobby Jones's success as to Jack Nicklaus's . . . arguably, it was MORE important back in the day when it meant the difference between a 4-iron approach and a 7-iron.
From 1987-1999, 8 of the 13 US Open winners ranked outside the top 100 in Driving Distance on the PGA Tour. Since then, from 2000-2022, Only 3 US Open winners ranked outside the top 100.
The US Open didn't always reward length, But it did reward great play. The shorter players winning these events were some of the best players we have ever seen. Hale Irwin won 21 times on the PGA tour. Curtis Strange won 17. Corey Pavin won 15 times. The only active players on the tour with more wins are Phil, DJ, and Rory.
From 2016-2022, 6 of the 7 US Open winners have ranked in the top 20 in driving distance. Over the preceding 29 US Opens, There were only 5 who ranked in the top 20.
We're currently in an unprecedented time for the US Open, as it now so clearly favors length. Is it a coincidence that during this time, the USGA is also widening fairways and shortening rough, or are they related?
This trend is not unique to the US Open, the story is the same for the Masters and PGA Championship as well. From 1987-1996, Players who ranked outside the top 100 won 19 of 30. Since then, only a handful have done it.
Earlier this spring Mark Broadie published a white paper where he examined the
impact of distance change in professional golf. Examining data from 2004-2022 Broadie found that over the past 2 decades Driving increased from only a ~19% contribution to a 28% contribution towards scoring, while Approach play decreased from ~41% to a 36% contribution. Driving was the only category to increase in contribution to scoring. If the trend continues, will become the most dominant contributor to scoring in less than 10 years.
So yes, the game has changed. Length and power are much more important than they used to be.
Now we all know some courses favor certain types of players. Some are approach play courses. Some are short game courses. Some are accuracy courses. And some are bomber courses. It's the golf course architecture which decides which part of a player's game will be favored, which part will be rewarded.
Therefore newfound supremacy of length in the top levels of the game is very much an architectural issue. It's definitely just as much an architecture issue as it is a technology issue.
If you truly believe thick rough and trees worked fine for the best 10% of golfers, would you please let everyone know that. People listen to you. The game is changing quickly in front of our eyes at the top level, and letting the USGA know there is nothing wrong with trees, rough, and tight fairways on courses meant for the best players in the world would be huge in bringing a balance back into golf at the highest level.