But possibly you are exaggerating what VAR used in its current format is capable of and that's why it's not reaching your standards, and you've run out of patience based on that. Fundamentally VAR can only increase good decision making, it can't ensure perfect decision making. Whether it has done that is something that requires looking at all the data, not just gut feeling or reference to specific examples of inconsistency that you mention. We are always going to have examples. Every club has hard luck stories.
The issue is football isn't cricket where sets of eyes on a replay near guarantees correctness. There is black, white and then grey in football. VAR is most impactful where it is black and white, i.e. offsides, and is still reliant on subjective opinion for the majority of match incidents. I don't see unanimous takes among astute observers of football on difficult decisions and yet they expect this degree of precision week to week from a referee or VAR. Maybe there should be a realisation within that about human observation of incidents and the inherent fallibility, one that doesn't require corruption, bias or bandwagon following to explain. Although clearly they are probably impacted by constant references to them in the media, because again... that's human fallibility.
But VAR aside, none of this should justify abuse from players and managers, it's really a separate issue and we need to separate fair criticism and creating a horrible environment for referees to perform under. As you mention, yes crap decisions should be called out at the right time and place and in the right manner. But it's not a case of "do your job well and you get respect." It's that a baseline level of decent treatment should include not being abused and threatened at work, and it says more to me about the character of those doing it than it tells me about the refs performance.