Reckon VAR will take years to get right.
Once it works it will be great but I think as a sport it will have to take some pain before it improves.
The problem in its essence is two-fold;
If the referee has referred to VAR (in particular the touchline screen) they will have already initiated a line of thought in their mind which will lead to instances of confirmation-bias, whereby the referee is only looking for proof to confirm their suspicions, rather than reviewing the incident objectively
Secondly, it is possible to over analyse incidents, particularly with extreme slow motion and different camera angles etc which can lead to even more ambiguity and/or make incidents look completely different to how they actually were in real time - leading to bizarre decisions. We saw that at the World Cup with hand balls given because in super slow motion it looks deliberate
Also add in issues such as timing for decisions and communications with players and fans