To take one example, the details of rental car controls can sometimes be unfamiliar. I've generally been comfortable pulling out the manual in those situations, but I'm sure some people would prefer a live walkthrough, if available.
Seeing the rep makes sense, but the rep doesn't need to see you. Unless you've broken off the car controls in your hand and want to show them. Otherwise it seems rather a massive net negative.
I was thinking along the lines of a five minute video clip available when you rent- kind of a training, if you will, like they have for personal watercraft. Optional, but available.