The skill gap between Hellebuyck and Comrie is substantial. If you've been watching the games, Hellebuyck looks like his regular self when the Jets are playing to their system. As soon as momentum shifts and Jets can't clear the front of the net, defend the slot, or cleanly exit our zone, that's when the goals pile on. He's had a couple bad goals against, but most GA are from a systematic collapse.
Vegas is a good example of a team that excels because their system. When we've played them in the playoffs, they keep the slot clear, they win board battles and keep their opposition to the perimeter, limiting high danger chances. It's how the Jets won during the regular season and one of the reasons why Jets goalies post good stats. If you need proof, compare Comrie's stats over the last 5 years, it's inflated from playing in the Jets team defensive system. A collapsing system where the team defense comes unraveled with Comrie in net wouldn't yield us a better result than Games 3,4, or 6.
The problem is with the heightened energy, momentum shifts, physicality, and tenacity of the playoffs. The Jets skaters start to crack and it's open season for high danger chances and berserking Hellebuyck.