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.
The “correct decisions” argument is evidently bollocks anyway. Just watch any PL broadcast when you’ll get some ex referee claiming that the officials have got a decision right when everyone can see with their eyes he’s talking absolute bollocks. It’s pure gaslighting.