Wow, this has aged TERRIBLY in a decade
I never thought the movie was amazing, so maybe I'm biased a bit. But I decided to check it out for the first time in a decade to see "what started it all", and wow, it's bad. So cliched, so dated, so generic. The "jokes" almost all fall flat (quirky improv is barely humor), so many of the "dark" moments are just cringeworthy and wannabe-edgey (Loki attacking the museum with ironic classical music playing in the background) and worst of all, the CGI is fucking atrocious. The final attack scene is nearly unwatchable because of how terrible that CGI looks. Everything looks like either a video game cutscene or like people are standing in front of a green screen.
I think the hype was SOLELY based on the fact that nerds were excited to see multiple heroes in one movie fighting alongside together. Almost all of the archived posts from 2012-ish are all the same: "wow, it's just like the comics!!! 10/10!!!" Had this come out today, it would get brushed under the rug pretty quickly. Hell, hardly anyone talks about it anymore and it fell out of the Top 250 years ago, so maybe I'm not wrong.