First of all, let me say how much I admire you. Pursuing an abuser through the courts takes courage. As for it being a waste of time, that's not true. This will hang over him for the rest of his life. Only the worst kind of filthy paedophile, the sort whose life is spent in and out of jail, could be unaffected.
People should hound these b*stards, whether it ends with a conviction or not. Even if someone reports a historic case, and it's dropped for lack of evidence, it is still worth doing. For a start, the abuser must confront what he has done. Even if he denies it, and tries to wriggle free, it still means admitting it to himself. Of course, many people genuinely don't care. But most live with what they've done by denying or repressing it. Since no one ever complained, they can convince themselves that it really wasn't so bad, or that it wasn't even abuse. When they have to go to the station for questioning, however, they're forced to accept that someone really was hurt – and that they did wrong.
Also, don't forget that a prison sentence isn't always the worst punishment. The worst bit is having to face your wife, parents and children. I remember watching a documentary on 'Operation Ore,' for example, which was the largest ever crackdown on men viewing child pornography. One of the policeman was asked what he thought of their sentences, and the fact that most were let off with a warning. He replied that the real punishment came outside of the courts – the end of their marriage, their friends not talking to them, their children being asked if daddy had ever touched them, etc.
I have known several people who were abused. Not one of them went to the police. And no doubt the men who did it are now happily married, with successful careers and high social standing. And no doubt they sit in the pub and shake their head in disgust when friends talk about Jimmy Saville or Harvey Weinstein. Meanwhile their victims are scarred for life. It makes me so **ing angry,
I would urge anyone who feels up to it to report abuse, no matter how long ago it happened. For all you know, the a*sehole could be abusing someone else this very minute.