This is true, but Brodeur also relied heavily on preventing shots against. It's unfortunate that possibly his strongest skills can't be measured by a stat, but the guy prevented more shots from being taken at all over his career than he probably stopped. I don't care what era he played in, those skills would still let him excel. Most goalies don't pass the puck as well as a lot of defenseman, aren't mobile enough to use that passing regularly, and can't direct rebounds to the stick of his own players. Watch how many times Brodeur would prevent rebounds by kicking the puck off a shot right to his own guys to start a breakout, or how he would prevent the other team from getting zone time at all by retrieving the puck and passing it forward.
Brodeur is not the best goalie ever at stopping shots, but he's the best team goalie ever for his ability to control so much more of the game than a typical goalie does.