Most important position on the team? Really? When was the last time the vezina winning goalie won the cup? Or when was the last time one of the highest paid goalies in the league won a cup? Yes it is crucial to have a reliable starter, but they don't have to be the best in the league or even top 5 in the league to win. In fact it usually comes down to a somewhat average goalie have a hot streak at the right time. It's also more about how the defense plays in front of them. Of course this is all just my opinion.
Sure, the collective can compensate for a bad goalie to an extent. But if we're comparing individuals and their positions, the goalie has more impact on the game. For example, look at Niemi for us a few years back. When a goalie plays like that, there's absolutely nothing you can do. If Letang has a horrific night, we can still escape with a W. I've seen it many times. Hell, he had a pretty f***ing bad season and we still made the playoffs in 2018. Same goes with Crosby. He can make errant passes all night, but the team can mitigate the damage and win.
The only reason people say 1D's are the most important is because they take it for granted that the goalie will be at least serviceable. That's not always the case. Look at Darling for Carolina. You CANNOT make the playoffs like that, at least if he plays that many games. There's just no way.
