Fair enough on the other points - I get lumped in with being a VAR apologist but I feel like I'm one of very few that does recognise it has its limitations.
As for the bit in bold, to avoid the howlers and obvious mistakes is quite an obvious reason to have it. A by-product of that, however, is the questionable margin of where do you draw that magic boundary line of what is a howler/obvious mistake, what's close to such an embarrassing mistake but is still a mistake, and what isn't a mistake that gets verified by being checked. VAR covers all - I said earlier I don't think scrapping it is the answer because we're all on about an entertaining spectacle but I can't believe anyone that says they'll be happy when it's gone then see a utterly disgusting decision go against them, and then not be livid with it as they walk out of the stadium.