My concerns over VAR go back to when it was just a glint in the eye of the authorities. Yes, it could cut out some bad decisions, but only at the expense of interrupting the flow of the game, imo - and that's something I don't want to see. Now it seems that they don't want to do that, so the advantages of it are being lost. Add to that the reluctance to undermine the ref, and it's just a mess atm.
Perhaps it will improve, but I still don't see how the momentum of the game can be maintained whilst also correcting bad decisions.
In theory it should help with offsides, but it's far from perfect even there, because players are having to continue long after a decision should have been made.
The incident in our game with Arsenal springs to mind: Aubamayang was clearly offside, but there was no flag - belatedly Matip flies across and blocks his effort. One or both players could have been injured in such a challenge, when the whistle should have gone earlier to prevent it happening.
Moreover, a corner was given from that challenge, so what happens if a goal results?
It's just not as easy to implement as some people were seemingly expecting - it's neither fish nor fowl atm.