I've said it before, but ENDGAME on a basic level does feel a lot like an adaptation of the comic series AVENGERS FOREVER by Kurt Busiek, with the Avengers visiting multiple time periods and a huge Avengers battle at the end.
Of course it's a bit different because FOREVER featured multiversal Avengers but it still seemed fairly similar to me.
Also Cap finally saying "Avengers assemble" seems like a moment comic fans had wanted to see since the first film.