It's literally the only big pop culture event taking place right now and it has no competition. Release this in a normal year in the summer, when other blockbusters are coming out and I don't see it happening.
It's a good movie with some good gimmicks to mobilize the fandom, and geekdom. However we haven't had a really good MCU flix since 2019. Black Widow was meh. Shang Chi was ok but not top tier Marvel. Eternals was well hopefully a prologue to something better. Though they all did seem to serve to wet the palate for something more substantial.
I'm thinking this was pent up demand in the way that Force Awakens was for Star Wars combined with FOMO, ala Avatar and it's "new vivid 3D" that was a first at the time, and lack of alternatives.
Obviously their risk in releasing it is paying off. It may lead to other films being released in greater frequency now.