Agreed.
Honestly, I think it's at least another fifteen years before we see Endgame's opening weekend record fall. It will take a level of hype and build-up that only a long-running franchise can match, and there's just nothing in the next few years or so coming for the build up to even begin, that will be able to unseat it.
That said, I can potentially see the domestic record falling sooner. Because, technically, that record doesn't need pre-release hype to be broken. It's not likely - but it is feasible - that some kind of "surprise," Titanic-esque blockbuster can come along one December, speak to the zeitgeist in some perfect way, and then, based on word of mouth, stay at number one through February or so. Again, though, that would obviously take lightning in a bottle, but it's not completely out of the question.
Other than a surprise, earth-shattering hit like that, if, if, if, if, if Episode IX is somehow the greatest Star Wars movie ever, I think it's the only franchise movie for the foreseeable future (the next decade or so) that even remotely has a chance. Otherwise, yeah, Avatar 2 isn't going to take the record, and the only other worthy franchises I can think of would be Batman and Fast & Furious, and I don't see either one of those doing it. Otherwise, Universal has botched the Jurassic Park/World franchise, Pirates of the Caribbean is dead, Transformers ran its course, and Fantastic Beats hasn't come close to matching Harry Potter's success.
So, yeah, if not a surprise, monster hit, I say it's...
A) Episode IX (which has maybe a 15% chance, if that)
B) the third entry in a future, somehow-universaly-adored Star Wars franchise, which would be 2026 at the earliest.
C) a new Marvel team-up of some sort, even though you can already start to feel the air coming out of the tires just a bit in the wake of Endgame.
In other words, if I had to bet, barring some surprise hit, yeah, nothing takes the domestic record down until sometime in the 2030s, and it'll be something we can't even think of yet.
