The thing that strikes me most about Crosby advocates is that they clearly place an enormous amount of value on team success, which Crosby has had in spades. However, all of that team success was front-loaded into the early part of his career, and they pay little attention to the fact that Crosby's team has won exactly 1 playoff series since he turned 30 prior to the 17-18 season. If anybody had stated after Crosby's age 29 season, when he'd played 148 playoff games, that he still wouldn't have 200 playoff games played at age 37, they'd have been laughed out of the thread. Crosby's played 32 playoff games in the following 8 seasons, despite being healthy enough to play about 92% of Pittsburgh's games in that time period. Mario Lemieux, who initially retired before his age-32 season, actually has played more playoff games after turning 30 than Crosby so far, playing in 41 games (and winning 4 series).
The other aspect of team success is regular season results, and again Crosby's career is a bit disappointing. His team never won the President's Trophy, finished 1st in his Conference once (and that in a shortened season), and won 4 or 5 division titles, depending on tiebreakers. To be fair to Crosby, he does have 6 second place finishes in Conference, though none since 2016-17 (again, before he turned 30).