Before watching the movie:
I only very recently, perhaps in the last year or so, learned that this movie is a direct reboot of the Universal Monsters version of Mummy lore. The original Universal Mummy may have greatly influenced popular perception of mummies, but it’s perhaps the most generic legend in the franchise. Even werewolves, which are perhaps more independent, have a greater connection to The Wolf Man than mummies.
Additionally, I always thought of this as a fantasy action film, while the 30s film is, like the rest of the 30s and 40s films, definitely positioned as horror. Perhaps the genre shift accounts for the unpopularity I perceive this movie to have, though I’m not sure it’s actually all that unpopular, considering it had a handful of sequels and starred Brendan Fraser at the height of his fame. On the other hand, maybe the sequels are on the strength of the overall franchise. I may understand better after watching.