Has it though? I know a lot of cricket/rugby fans complaining about use of tech. Yes it has improved them but there are still plenty of decisions going wrong and if that is the case I wouldn't call it a successful implementation.
I read a cricket fan comment a few days ago praising the VAR system because reviews are left in the official's hands. Grass is always greener on the other side.
Are decisions going wrong, or is that one set of fans don't like the decision, and therefore say it is wrong when it isn't?
A bit like a player being offside by a couple of inches, everyone is complaining about no one wanting these types of very close calls being given and that it is because VAR is rubbish, but they forget that the play was offside and the decision was correct.
I regularly go to international games at Cardiff, I don't think I've ever seen a decision that was wrong, or that a majority of people were unhappy with, except in cases where they are trying to see if the ball was grounded but none of the camera angles can say one way or the other due to players being in the way etc.
Also, lets not forget that cricket decisions by their third umpire are pretty much all factual, i.e. did the ball bounce just inside or outside the boundary, was the batsman safe, did the ball touch the ground or did the fielder catch it just before it touched the ground.
They also use a lot of technology, Hawkeye (same system used in the premier league for GLT, and tennis) is used to plot the predicted path of the ball when it has been interrupted by the batsman, ultraedge that uses microphones to see whether the ball hit a bat or pad, and hotspot which shows where the ball has been in contact with a bat or a pad.
I would suggest that most people who complain about VAR in sports like Rugby or Cricket would change their tunes pretty sharpish if their sports suddenly stopped using it.
VAR in football is going to take years to perfect, and this is what the clubs wanted, they don't care about the fans, only about the money that (what they believe to be) incorrect refereeing decisions has cost them.