Back in 2012, there was an idea to bring together a group of remarkable people, see if they could become something more. That wasn't only true in-universe of the superhero team but in business terms for Marvel Studios and their Disney paymasters and boy did it deliver.
Despite having lots of things riding against it - the unenviable need to balance lots of moving parts, a satisfying escalation to justify the team-up and also the perpetual, cynical suggestion of a superhero bubble pop - the movie made an absolute fortune and made Kevin Feige's dream of a shared universe a reality. It was not only incredibly entertaining, but also hugely important as a keystone of the MCU's further expansion plans.
As a side note, in some markets, The Avengers was called Avengers Assemble, which might be the most needless and annoying title change in the history of cinema. If it was done in order to avoid links to the Sean Connery/Uma Thurman movie, then everyone who thought it would be a confusing problem ought to have been fired.
So, what did we learn from rewatching the first super ensemble in the MCU?
The Loki who initially appears in The Avengers is far removed from the "brainy weakling" archetype he becomes in Thor: Ragnarok. Yes, he's conniving and blade-sharp, but he's also a bona-fide bad-ass too. His first appearance is a reminder that Asgardians (and Frost Giant runts) are genetically superior to humans in every way.
He smashes his way in, kicks a soldier away almost effortlessly and seems immune to bullets, and later he manages to beat Captain America up. Very few characters manage that - it's like he's a different character entirely.
But along with that tougher edge, Tom Hiddleston also offers depth and nuance to the performance. Watching him and Thor argue towards the end on Stark tower particularly shows that, and the fact that Loki sheds a tear - almost accidentally - is testament to that subtlety. This is why he's still beloved as the MCU's best villain.