I have been playing golf with my son for the past few days. I use the 2005 titleist driver and he uses the 2020 titleist driver, pretty much the same model. Using my 2005 driver, he can drive the ball 250 yards. With his driver, he can drive the ball 280+ yards on a consistent basis, just saying.
This response tells me you're at best a 3.5 tennis player and at best a 18-handicap golfer. You know nothing of either sport and the changes. I'll help you...
Tennis: The number 1 change has been strings. After that, the racquets have been made lighter and lighter but nothing more. The technology of the racquets has done little and that's why many professional players still play classic frames underneath modern paint jobs.
Golf: There have been so many changes from ball dimple design to shaft to club head materials. Since the ball and the swinger are the same, one can only assume the shafts are different; different kick point, flex/stiffness, weight, and possibly even tip diameter and length. Since the regulation on size has been set, the face thickness could be much different and the variations allow for much more flex and trampoline. Take a 43"-48" club and the changes can be numerous.
The changes in a 27' racquet with an 16/18 x 19/21 racquet is not much. My favorite is the difference between a 98/100/104 racquet head. The naked eye can barely distinguish a difference but nearly all of us can feel the softer string bed.