Look, bad people do bad things all the time, and you do not always have legal recourse for justice. Robberies can’t be proved, you can’t identify assailants who mugged you, the police are unable to find your stolen car; whatever.
Personally, I have only ever gone to the police once when a crime has been committed against me, and in that particular instance, the culprit was identified, caught, and released for lack of evidence.
It happens.
It happens because the world is not your living room.
If something bad happens to you, and you do not report it because you know you can’t prove it, well, ok, that is something that happened. What do you do then? You cope. You adjust your own approach to the world according to your new awareness of its dangers.
If you couldn’t prove at the time that the crime occurred, you certainly won’t do any better at proving it years later.
If you believe in the rule of law, you do not take your allegations to the court of public opinion, where the standard of evidence is low enough for you to potentially get your revenge. That is almost subversive in its belittlement of the law, and by definition, such tardy accusations should be immediately suspect, unless of course, the delay is due to having been a child at the time when the alleged crime was committed. Otherwise, your delay is just a device for trying to minimise the expectation of the burden of proof, which is the hallmark of a false accusation.