sadly var was set up to let another referee give an opinion
No, it was set up to give the R the chance to fix clear errors. It is the R, not the VAR, that decides to review (after the check the VAR can only recommend a review to the R), and it is solely the R's opinion that matters. (Where the issues is black and white--like OSP or GK off line, there is no opinion involved, as it is simply a determination of an objective fact.) The purpose was to catch those blatant errors that everyone who watched new was a mistake but the R had a bad angle or didn't see or for some other reason missed an obvious call.
but at the wwc they are getting it badly wrong
Too simplistic. Yes VAR has created insane delays at times. But the biggest things people seem to complain about on VAR related calls are not really VAR issues, but complaints about the underlying rule. VAR is not wrong on GK movement--the rule is the rule and FIFA decided it wanted it enforced tightly. We'd be having exactly the same conversation about those calls if the ARs had been tasked to call that. (And it is a bit mystifying, given that the VAR protocol says calls are always made on the field, that ARs have
apparently been told to leave that to VAR.) And the biggest brouhahas have been about OS involvement--but that is not really about VAR at all, but about a disliking the dictates of Law 11--and improperly blaming that on VAR when the VAR properly raises an issue.
I'm not a fan of VAR at all. If I were in charge it would be gone instantly. But much of what we see in the WWC is inherent. The pretense that there is always a right answer. The fact it takes time to look at video. The fact it then takes more time for an OFR. The pretense that video reduces controversy. (Video can reduce controversy on objective decisions--it works great in tennis where the question is if the ball hit the line or not or american baseball to see what happened first, and indeed can very precisely determine OSP in most cases. But on subjective decisions (and soccer is unique in the scope of subjective decisions that can be reviewed), there is
never going to be 100% agreement on any but the simplest of calls, and anyone who thought about this in advance knew that. And that, if anything, creates more controversy, as there is no longer a "the ref had a different angle" issue--everyone gets to see exactly what the R saw.) FIFA got lucky in the MWC that the biggest issues of VAR didn't come into play at a critical time. Not so lucky in WWC.