A large part of a goaltenders success relies on the team in front of him. Statistics are the result of your technical ability coupled along with the team in front of you & the quality of the defense, along with some puck luck. Not all shots on goal are created equal.
His statistics stand on their own not only in the regular season, but in the playoffs. That coupled with his actual technical ability, he's one of the top in the world. It's just a fact.
Still doesn't make sense.
First off everyone claims the Kings have a good defense. Second regardless over a huge long term 6 year sample size it is a safe assumption that all goalies face a similar spread of shots provided we are not on huge outliers such as a team with league worst defense 6 years in a row which is not the case here. That scenario over one assuming Quick only facing very tough shots and other guys face soft shots is by far more realistic.
We're not talking about a month or two of marginally above average results we're talking about an entire career where he's had one super elite season, one marginally above average, two ~average, and two pretty far below average.
Additionally given he has ranked 25th/26th or so for two years in terms of sv% among goalies who played in at least half their team games that almost automatically means their were goaltenders who put up better stats despite playing on worse defensive teams