I think that over all VAR worked well.
Thing that I don't like however is the penalties for the ball striking a defenders hand when it is clearly not deliberate.
I also wonder about a couple of corners which were given as goal kicks. Both were obvious immediately and why didn't VAR simply correct those and get them right?
So the second part is easy - they decided that VAR would only be used for goals, penalties, red cards and cases of mistaken identity. Not for corners, free kicks or anything else. Which makes sense to me, as I think you only want to use it for the highest profile errors. Over the course of the tourney, VAR only intervened about once every four games. Expand it to lesser decisions, and you're going to see that multiply in a hurry.
On the former issue.....I'm actually not sure it's a reflection on VAR, as how subjective the handball rule is at the moment. I mean I've heard dozens of opinions on whether yesterday's incident was indeed a penalty, and it seems to be divided about 50:50. The ref clearly didn't see the incident in real time, because when he did see it, he gave the penalty......
Did Perisic move his hand towards the ball? If not, why was his hand out in front of his body if he wasn't intending to use it to block the ball?
Frankly, there's only one person in the world who knows for sure if he deliberately - even if only for a split-second - tried to handle that cross. And he ain't exactly impartial.
Until we have mind-reading technology, perhaps the guidelines need to be simplified a bit i.e. if your hand is away from your body, and it diverts the ball, then it's a handball.....force players to keep their hands down by their sides if they don't want to be at risk.....