If Infinity War is a straight-through cohesive masterpiece with every part being memorable, Endgame is a good movie with some good memorable parts. Some of the direction they took just didn't gel with some of the characters as we know them to be, both through the MCU and the comics, humor chucked in at wrong parts, and all-in-all it felt a bit rushed. This should have been a three-part storyline to allow for further development, three hours was not enough. If you are a viewer who respects the comics, appreciates the MCU and thrives on great story-telling, you will understand once you've watched it. This movie is no Infinity War. It's a good movie, yes, but it is not an epic movie.
I left a bit underwhelmed. Fan-service is one thing, which they did deliver, but at the sacrifice of a memorable finisher to 10 years of cohesive entertainment.