It’s nothing to do with VAR. You just don’t understand the handball law. You appear to be genuinely saying that if a player punches the ball straight to an opponent then it’s not a handball because they haven’t gained an advantage. It’s a complete misunderstanding of the law and it has never been interpreted in that way. As I said above, this type of incident (if spotted) has always been a penalty. I can only presume that the referee has wrongly taken the view that Greenwood handled it first, as that’s the only plausible reason for the decision today.
edit - as mentioned above, this is much more a penalty than the Pogba one versus Liverpool from 3-4 years ago, when he got himself in a mess and ended up handling it when he was trying to head it. So far as I can recall, there was a unanimous view that was a penalty, even though it was clearly an accident. This incident today is absolutely clear cut - it’s a penalty. It’s absolute madness that anyone is even debating this one.