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.
No. There is a clear pattern. And there are public statistics. Some teams get to the VAR actually fail on their favor, or not to be called for at all if it benefits them. One time it’s ok. Two still ok. But it happens too much and becomes a pattern. Ok, I’ll say it: it’s Real Madrid and Barcelona, at least from what I know