I completely disagree.
It was an outlier amongst all the modules produced by TSR
It wasn't like any standard dungeon adventures which I played in, or read about in various APAs of the day.
Thus it is, by definition an outlier.
In addition, I never considered it to be a particularly interesting or 'fair' dungeon, designed with too many instant death effects. Ran a quarter of it once, and it was wholly boring.
It can be considered an outlier because it was the first AD&D module and Gygax intentionally made it incredibly challenging for players, surpassed only by
Isle of the Ape. But it set the standard for all modules to come in both presentation and content. AD&D itself was about player skill, not character abilities. And those early modules demonstrated this. They may not have been death trap dungeons, but they were difficult unless you thought beyond your character sheet. And even with the game itself, you did not get much XP for killing monsters. You killed them when you had to and avoided them if you didn't. Otherwise you would get nickled and dimed to death.
Even the Giant series emphasized wit over raw character ability. If the entire Steadying of the Hill Chief got mobilized because the characters just charged right it, they'd get stomped. The Glacier Pits of the Frost Giant Jarl presented an environmental challenge that would foil uncautious and impatient players. The same goes with Hall of the Fire Giant King. These were modules for high level characters. Player skill was supposed to match these level. If not, then "thump."
The same can be said for lower level modules from those days.
The Sinister Secret of Saltmarsh required players to decipher codes and piece together clues leading to the next module. Again, this wasn't death trap, but it required player thought.
The Village of Hommlet required players to be incredibly cautious of who they speak to in town, otherwise those in moathouse would be on alert and ready. Heck, even
The Keep on the Borderlands required that players be cautious, otherwise their neophyte characters would be massacred.