if we think about the degree (instead of the existence) of the influence of strategy in deciding matches..
courts are getting smaller because -
1) athletes are getting faster
2) surface is slower
3) diminishing net play.
therefore not only the north-south dimension has been taken away for the most part, the east-west dimension has been made smaller.
therefore the less degree of strategy influence.
no doubt strategy is still a big factor today... survival of the fittest... I'd be curious to hear from coaches, on the time devoted in training, to the ball striking part vs. the strategic execution part..... today vs. many years ago.