I guess the competition (i.e., Detective Pikachu, John Wick: Chapter 3, Aladdin, Godzilla: King of the Monsters, etc.) were more than enough to slow down Endgame.
Regardless if it was able to pass Avatar or not, Endgame's incredible run to $2.7 billion and 2nd all-time in box office gross is nothing short of incredible. A lot of people expected big numbers, but probably not to this extent. It shows that the MCU's brand power is even stronger now and any popular movie series can reach such potential with the right marketing, the right production team, the right casting, and the right execution. It's difficult, but it can be done if given the type of care the MCU was given. Hell, I am not sure if anyone would have ever thought Avatar's record would have come close to being broken, let alone almost past by a comic book superhero movie, which have had their success stories, but nothing like what the MCU was able to develop.

[see above] agreed.

When taken as a whole, the entirety of the MCU dominates. There's some major records out there.

Go Marvel!! Em-Eye-See-Kay-EE-Why Em-Oh-You-Ess-EE

Is this actually true, though? Most moviegoers liked the movie. It will spawn four sequels, stage pieces, theme park attractions and shaped the movie industry for years with 3D.

I'm not sure what some folks actually expect. How often is any of the blockbuster movies of the past decade discussed? At most there'll be a Joker or LOTR meme here and there if the conversation is geekish enough... and these are from multiple-movie franchises.

There's a 4 quip minimum here, per hour.  Or you get kicked out of the club.  Then, we'll invite you back in, just so we can kick you out again. 

j/k j/k!!  :)

[edit: we don't talk about the club, either.  there is no club.]

Sequels have been declared but we have no idea whether they will succeed or not. The first movie was successful because of its technical achievements, which cannot be scoffed at, but it does mean that it wasn't necessarily successful due to the design, story, and quality of the movie itself. 

I wasn't referring to pop culture as online discussion necessarily; when I mean a pop cultural impact I mean references to it from other media sources as well; like shows, movies, podcasts, Late Night shows, and so on. Comedians, mainstream nerds, and others still refer to Lord of the Rings regularly; and Titanic is still referred to in shows and sketches. Beyond references in other shows, movies like Gone with the Wind are still quoted, and you can see how the mood and aesthetic of the movie influenced other movies that followed. 

I guess what I'm trying to say is, for the best-selling movie of all time, like was Gone of the Wind before it, Avatar did not influence a lot of media that came after it. It was the first to do 3D very, very well - but that is not about the artistic value of the movie itself but rather it was the first to capitalise on the advancement of technology. The story, aesthetics, atmosphere of Avatar really did not leave an impression. You can't really trace its DNA in other movies and media after it. I find this interesting because, again, its technically #1. Endgame for sure has a larger cultural impact than Avatar ever had. 

That just shows it sold on 3D hype/word of mouth and nothing else. The only thing people will remember is that it's the one with the blue alien things. MAYBE they will remember that they were called the Navi, but that's it. No one remembers character names or quotes that film. It's amazing that Cameron thinks he'll spend the rest of his life making Avatar sequels. If he's lucky, the 2nd one will make half as much as the 1st.

Dark Phoenix not being that good could should help out Endgames legs a bit.

I think I'm one of the few people who hope it doesn't pass Avatar. For me, Endgame wasn't the movie that tops Infinity War in quality, as it should have done. And I really loved Avatar.

The reason why Avatar hasn’t had the same cultural impact is because it’s from 10 years ago and has no follow up material. Marvel movies come out like every couple of months and has lots of additional material. You’re talking 1 film compared to a franchise universe with an entire corporate machine constantly backing it.

That's another topic which would be interressitng to discuss about