I actually think it seemed to work well in the world cup because it didnt involve too many 50/50 or ambiguous decisions. It was also a small sample size of matches over the course of a month. The issues with VAR become more apparent over the course of a full season.The shit show that is VAR in the A League has been a disgrace. VAR as was applied at the World Cup was terrific. The system can work well and be as seamless as possible, if correctly used. As in any work place, an employer needs to give the necessary training that is required for an employee to fulfill their responsibilities. FIFA prepared well, Football Federation Australia did not.
For instance, I'm not convinced a hypothetical implementation of VAR would issue a red to Maguire the other night. I've already read numerous opposing views on that decision. And to a lesser extent, the Keita penalty decision.