"Corroboration" doesn't mean there has to be a witness, it just means there needs to be corroborating evidence, not just he said/she said.
I was on the jury for a rape trial once. We acquitted because, in the jury's opinion, the evidence (e.g. CCTV before and after, ME's evidence/photos, inconsistencies in witness statements) corroborated his account that the sex was consensual.
I understand how difficult it is to even get a case to court, never mid convict, but I don't agree with getting rid of corroboration.