"Better" isn't just about increasing benchmark numbers. Often, it's more important that a system fails safely than how often it fails. Automatic speech recognition that guesses when the input is unclear will occasionally be right and therefore have a lower word error rate, but if it's important that the output be correct, it might be better to insert "[unintelligible]" and have a human double-check.

Ideally, you'd be able to specify exactly what you want - do you want to write-out filled pauses ("aaah", "umm")? Do you want to get a transcription of the the disfluencies - re-starts, etc. or just get out a cleaned up version?

It's better in terms of WER. It's not better in terms of not making shit up that sounds plausible.

Probably the answer is simply to tweak the metric so it's a bit more smart than WER - allow "unclear" output which is penalised less than actually incorrect answers. I'd be surprised if nobody has done that.