Not an expert either but what I do know is the only way to return some of those shots is to be able to predict in advance the likely trajectory and bounce of the ball based on a number of subconsciously observable criteria (body / hand / arm position, racquet position, previous shots, sound even??). Roll in an element of unpredictability in terms of balls that bounce differently (both off the racquet and the ground) and they’d have no chance.
And there’s something quintessentially posh about the term ‘New balls please’.
And there’s probably a ton of money to be made from balls used in championship tournaments.