Has it? It has pretty clearly been the clear weakness of the roster and arguably why they have never gone as deep as they should have. No matter how well they defended when they got to later rounds, the other teams could defend that way as well but had way better goaltending.
2018-19: Wild Card, beat Metro #1 Washington and Metro #2 NYI, lost to Boston in conference finals. Deeper than they "should have" by any metric.
19-20: 6 seed. Beat the rangers, lost to 4 seed Boston in the second round. Not overperforming, but certainly went as far as they "should have" based on regular season results.
20-21: First divisional title. Beat Nashville in the first round, lost to defending and eventual Stanley Cup champ Tampa in the second round. Finished 5 points clear of Tampa on the season; a tough match but not a shocking upset by any stretch especially given it was the defending champs who went on to win it all.
21-22: Second divisional title. Beat Boston in 7 games, lost to the Rangers (6 points behind in the regular season) in 7 games with their second and third string goalies after a late season Andersen injury. Again, they "should" beat the Rangers with their 2nd and 3rd string goalies? This is the one where goalie may have cost them, but due to an unfortunate injury.
22-23: Third divisional title. Made the conference final, beating the 2 seed Devils in the second round. Lost to the great Florida postseason run in a series where Andersen was outstanding in goal.
23-24: Metro #2, beat metro #3 and lost in 6 to the divisional winning Rangers. Again a close race (only 3 points difference) but not a "should have gone further" when you play the President's Trophy winner in the second round.
In short, the "upsets" were defending Stanley Cup champs in Tampa, a Rangers team 6 points behind them while playing their second and third string goalies, and the Florida run that started with beating the best regular season team in a generation in Boston. Hardly shocking upsets that were indicative of major issues.
Saying this run in total is an example of "never going as far as they should" is simply intellectual dishonesty.