Endgame 6/10, being generous.
As said above, had some moments. Was bored far too often, they try to take themselves too seriously, then have bullshit jokes everywhere. Understand it's hard to balance when they have all these "heroes" merged into one movie. For example, Guardians of the Galaxy is a comedy and I expect it to be, Captain America is not a comedy and his movies don't feel like one either (although they all have silly jokes in them). With Endgame I felt like I was watching a comedy most of the time.
It's a shame, as I really liked Infinity War, which was a solid 8/10.
The only positive from this film is that Thor is with Star-Lord, those 2 are great together and I expect Guardians of the Galaxy 3 to be Thor 4, or they'll mix the names somehow.