Marvel's Avengers has been a roller coaster of a game from the announcement all the way up until its launch today: so long as you're a Digital Deluxe owner.
We first heard it existed back in 2017, but when Square Enix showed it off at E3 2019, people couldn't believe that it was nearly finished. It didn't look finished, that's for sure! The publisher seemingly agreed, and pushed it back further a few months, citing the need to polish it more.
It probably could have used a bit more time, but with Marvel breathing down their neck, it's possible they got as much as they were allotted. Today, we get what we get. And there's plenty of fun to dig around for in this oddity of a game.