Imo VAR should only exist in a technical capacity to prepare footage to transfer onto a ref's portable Fold 5 or something. Samsung could sponsor it even!
The decisions should all be made by the ref on pitch and this would massively improve the speed of play during VAR. There's no reason they should have to walk off pitch.
As a Wolfsburg fan, I'd like to say a thing or two about that. He left us to go to PSG!