The biggest way VAR is fucking the game may be the handball rule leading to far too many penalties. When I used to ref games there'd be handballs in the box all the time because no one at our level was a big enough dork to defend with their hands behind the back. I think I only ever once gave a penalty for it, for a goal line "save". There was probably always a hint of that even at the top level... "yeah, it clipped his hand but come on, he's near the edge of the box, the ball was travelling fast and it didn't really make a difference". But thanks to the technology the refs are under pressure to give penalties for the most trivial arm brushes. It's ridiculous the proportion of goals being scored this way. If every slight touch is being caught on camera, maybe it's time to make it an indirect free kick offence except for the most obviously intentional blocks.
The Premier League interpretation seems better than UEFA's as it has additional caveats that don't seem to apply in European competitions:
- The arm has to be in an "unnatural position" e.g. Michael Keane running along with his arm stretched out in front of him
- A deflection onto the arm rules out the handball in most cases
There are, as always, some issues with how the law is applied by different officials but I think it's a pretty good starting point.
I don't think either of the penalties last night would have been given in the Premier League. Ross Barkley, with his back to the ball, blocking Van Dijk's header with his arm is comparable to the penalty given to Man U. Copenhagen's I'm less sure on as Maguire is a very handsy defender in general and his arms were only outstretched because he was trying to impede the forward (debatable if that's a "natural position").
I agree with your general point though. I've only refereed kids games - where the most common handball is a kid getting scared and almost catching the ball - but when I used to play almost every handball shout was rejected with a "ball to hand" response. In elite football though too many teams and players are shithouses that would exploit such a simplistic rule which I believe is why we have quite convoluted rules.