I think there's a bit of a bias against some of the smaller teams, not because people are biased, as such... but because ANY picture or video can be 'interpreted' based on the underlying assumptions of the individual. There have been a few studies that looked into all this and they have generally found that some teams gain and some lose over a run of games... https://blog.innerdrive.co.uk/sports/var-and-referee-biases http://ftp.iza.org/dp8857.pdf That Pukki 'goal' being disallowed was particularly questionable IMO... I mean, that is SO fine a judgement as to be impossible to tell for certain so the original decision, WHATEVER it was, should have stood IMO. I seem to remember reading that Sheffield United have had FIVE goals ruled out for offside and that's in half a season, 19 games. Y'know, that doesn't look right... bearing in mind that they were originally given as OK.
Now THAT, I agree with. There are naturally inherent biases extant because the system is executed by human beings (unlike the goal line system). Now with VAR, you are doubling the number of people (with their biases) involved in the decision-making process. That can’t be better.