Also, when you don't find any evidence for something, it's usually because that thing didn't happen. Sure, in some cases, something happens and you still don't find evidence, but to assume that is usually the case is simply problematic for how the justice system works.
Cases like the OJ affair you refer to are terrible for the justice system, but this Mendy case is on the opposite end of the spectrum. Doesn't have anything in common.
Still, it's probable that not all women that accused Mendy lied full-stop. It's also possible that some are simply woke idiots that don't know the distinction between rape and consensual sex with no emotional implications. You have to be extremely dumb to not see the difference, but people are easily capable of that level of stupidity.
It's not that
no evidence is found. It's that there is usually never enough in rape to cross the boundary of 'reasonable doubt' (in UK law, this essentially means that you should not vote guilty as a member of a jury if you are not certain a crime was committed).
With something like rape, save videographic or physical evidence of an attack, due to the intimate nature of it and lack of witnesses for obvious reasons getting over that boundary is very hard. It almost always boils down to her word against his. It is one of the hardest crimes to convict for.
Then on top of that, you get those few women who do lie and plants doubts in the heads of jurors, and then you have the world-class legal representation of Mendy who will surely be pursuing any way possible to discredit victims.
Greenwood is a great example - despite everything we saw, due to his gfs non cooperation, the CPS didn't even feel they had enough to take it to court let alone secure a conviction. Would you seriously say with confidence he is innocent if I asked you, just because he wasn't convicted?
Rape is one of those crimes that we have to morally judge as the legal system is not effective at doing it themselves.