I'm old enough to remember the late 90s, and even though players have gotten a lot taller, tennis feels a lot less serve dominated than back then even though tennis players are a lot taller.
In the late 90s we used to think the top tennis players of the future would all serve like Rusedski or Philippoussis. When Andy Roddick appeared, I thought that was the tennis player of the future I had read about in science magazines and their articles about serve speed.
The matches of Medvedev, Felix, Zverev, Kachanov, Del Potro etc don't feel like acefests the same way Rusedski Philippoussis Roddick matches felt, only Opelka gives me that late 90s feel (I didn't enjoy).
Perhaps because of the bigger balls, slower surfaces, and tennis players being so tall gives them a greater wingspan to return what otherwise would be a serve.