VAR is working to a degree in the World Cup.
However, anyone expecting the same for the Premier League is wishfull thinking. Imho.
The differences between application are striking.
At the World Cup you have 4 additional Refs in a booth from different Confederations. A committee of Refs.
In the Premier League you'll have Kevin Friend in the Booth with Lee Mason on the pitch.
When you have the head, Mike Riley, of the PGMOL claiming VAR would only change about 2% of decisions...there's your answer.
Mike Riley beleives his crew don't miss calls. The same crew who work and train together. Go to meetings together. See each other face to face on a weekly basis. For a Booth Ref to tell a pitch Refs, Mate you've got that one wrong, isn't going to happen as frequently as what goes on at the World Cup. They will protect their own. Which is why Clear and Obvious will only be about 2% of the time in the PL.
Now if Mike Riley and the PGMOL would agree to have someone independant in the VAR booth from another country, well maybe VAR would change more than 2% of the calls. Mike Riley probably voted Brexit...so no chance of independant VAR's..
Something I proposed earlier is how I would solve the Referee situation.
Take the top 5 leagues : England, Spain, France, Germany , and Italy.
Take the top Refs from that League and rotate them every season.
So the English Refs would do..Germany one season, then Spain one season, then France one season, then Italy one season..and then rotate back to Germany...etc.
Obviously the other Refs rotate as well.
You never Ref your home league for a season. Anti Brexit proposal..:p
This way there is no club bias in a Refs decision. No ego to protect a League. It makes becoming a Ref in the top 5 league means more Euro experience. Gives them more experience at different styles of play. Makes them better Refs.
If a ref from England doesn't want to work that way, demote him/her back to the Championship and promote another ref.