It probably gets 95% of the calls right. FIFA says 99.3% but I don’t think so. Still, if it didn’t exist everyone would be crying to implement technology like they did before. Think of all the goals/no goals that have been rightfully overturned. Even if there are some horrible calls sometimes, the good calls outweigh the bad ones.
My biggest gripe with VAR isn’t how many calls it gets wrong.
It’s how many times we spend several minutes after a goal not knowing what the fuck is going and can therefore never properly and spontaneously celebrate
VAR doesn’t improve enough decisions to be worth the cost, in my view
Goal-line tech and fully automated offside make sense - the rest isn’t worth the cost