They can do stuff to the courses to make it harder. Narrow soft fairways, 6” + rough. Rock hard greens, add some strategically placed trees. The first three things don’t cost anything
The players just drive it right over trees and cut the doglegs.
That's what John Daly did when he won his first major. And Daly was only hitting it 300 then. He is exceptional like Nicklaus and Greg Norman as far as distance.
Norman was the tours longest accurate driver in his day and he averaged 280ish.
Players shouldn't be hitting 7 iron second shots into par 5s. That should be a fairway wood or a long iron.
Par 5s shouldn't have to be 600 yards +. Even that is reachable for these guys with mid irons now.