This is certainly true at the macro or global level but boy how I wish it were true here in the U.S. I think humans continually improve in just about any endeavor AS LONG AS the carrot is tasty enough. Here in the U.S., for the past 20 years or so, guys have really only been playing for either the love of the game, or they were just chasing some cash. So the evolution of the game has certainly taken a sabbatical here in the states.
Globally, anybody that's been paying even a little bit of attention knows today's top players do everything better than those from the past, with the minor exception being running balls at 14.1 but that goes back to the whole carrot thingy. I used to think Mike Sigel had the most picture perfect fundamentals and now I'll sit back and watch some of his old matches and I can't believe how often that cue of his goes flying off to the side. His technique would be pretty questionable by today's standards.
For a more dramatic example of how quickly fundamentals have improved compare today's crop of Filipino players to yesterday's. Efren, Bustamante, Parica, Luat, and company all had wonky cue actions. In comparison Orcullo has such a tight cueing motion and remains as still as can be. Now comes James Aranas and he practically plays with a snooker technique.
The bottom line is -- the top dogs today ALL cue better than yesterday's players.
Negative ghostrider. Bringing a ball back 10ft on cloth like mud, or running it 20ft around the table, took a stroke and precision we no longer see today. The best are the best period. Bring Buddy back in his prime. Take him half a day to adjust to fast cloth and springy rails, or Lassiter, etc.., and they could play anyone today. They cued the ball absolutely as well as today's boys. You really think they cue better than Mosconi. There's no one alive today, that can draw the ball around the table the way M did.