The problem of cheating is not resticted to tennis. You cannot separate tennis from the real world. Cheating by young people has become epidemic. I have heard lectures by the president of UVA and read articles on this topic. Sure there was cheating when we grew up but nothing like today.
A high percentage of the very top students cheat in school. The school pressures on kids are the same as the tennis pressures. Over involved parents helicoptering their kids putting tremendous pressure on them to succeed at all costs. Judging them by somewhat meaningless standards, what colleges did you get in, where did you finish in sectionals. If you were to tell a parent that their kid cheats in school or cheats in tennis the reaction is likely to be the same. They would get mad at the messenger and not talk to you again- and say nothing to their precocious child. That is today's reality. I don't see a way of changing it. Truth is that it is better for the development of the youngster to teach honesty, fairness, and sportsmanship- even when it costs you a grade or a few matches.