When you serve jury duty and the case involves domestic violence, you are explicitly reminded of this because most people will assume it is not.
Still, we end up with cases like Brock Turner where he does get convicted not with the victim's testimony but a mountain of corroborating evidence and national media scrutiny. And then receives what is essentially a non-punishment.
How can we know what specific pieces of evidence led to his conviction? I would assume the jury took into account the victim's testimony and the testimony of the onlookers who stopped him. What makes you say he was "convicted not with the victim's testimony but a mountain of corroborating evidence and national media scrutiny"?
But maybe there are such places.
Every case is different: witness testimony can be far more credible than photo evidence, dna evidence can be less credible than video evidence.
There is — as far as I know — no legal system in the world that measures the validity of a case based on the amount or type of evidence. You can absolutely be convicted on witness testimony alone in the US. That’s very unlikely but entirely possible under the law.
Of course, it helps if there is corroborating evidence, but there is no rule that says one cannot be convicted (in the US) based on a victim's testimony alone. It just doesn't happen often because usually there is some sort of corroborating evidence of a crime, and because it's hard to eliminate all reasonable doubt without any.
(I would be really scared to live in such a country, that strikes me a a recipe for disaster)
Is there evidence that this is more likely in sexual assault cases than others? Your post here [1] (and the post you are replying to) seem to suggest that it is actually less likely in these cases.