The plotholes that bothered me were Thanos and his whole army going through time with no Pym particles, despite that being a major plot point for our protagonists.
The Russo's actually addressed this one
in an interview:
Q: How did Thanos bring his army to the future?
A: There is a guy called Maw in his army, he was a great wizard. Thanos himself was a brilliant genius as well. Those two easily reverse engineered and mass produced Pym Particles.
My full but brief review, copied
from my other forum:
Avengers: Endgame - Spoilers will be in spoiler markings. There's a reason I waited a couple days before writing this up... so much to unpack. Did it live up to the hype? Mostly. It was a very good and enjoyable film... but what stands out the most about it is just how much it is sticking with me. You know how sometimes you hear a catchy song, and then it's stuck in your head and you can't get it out? That's what this movie has been doing to me for the past day and a half. It's messing with me on a subconscious level; I find myself constantly drifting back to it.
So it's long. And it's pretty distinctly divided into 3 parts. In the first part of the movie, you can feel the length; certain scenes are clearly moving very slowly. But it's intentional; it makes perfect sense given the things that are happening. You feel the weight of what the characters feel. But still, about a third of the way through, I found myself thinking "yeah this is fine, but not nearly the amazing thing I was hoping for".
The second part is an enjoyable heist film. It does a lot of interesting things, and there's a lot happening at once. It's still nothing amazing or huge.
Then the third part... there is one singular defining moment when the movie turns into the biggest, most epic, and hype movie I've seen in a very long time. For me, that moment is
When you see Cap with the hammer. It's just so good. I suppose the third part starts a bit before that actual moment, but it's a slower ramp up up to that point.
Is it a perfect movie? No. But it succeeds in a big way at 2 important things: Being a huge epic film filled with as much weight and importance as the LotR films, and being a very good ending to a 22-film saga. I really don't know if you could ask for a better way to really wrap up all of the previous 21 films.
So one thing I didn't like as much:
I didn't like that they went with a time travel route at all. Sure we all knew that it was a likely possibility of what the movie would be about... but given the way that they actually ended up doing everything; it turns out the writers didn't even need time travel. I am glad that they didn't just use time travel to change the past and undo everything that happened... that would have been worse. But since the plan was never to alter the past so that things never happened that way, then the same basic heist movie could have happened without time travel.. just make it so that instead of Thanos destroying the stones, he hid them somewhere. And then instead of fighting past Thanos at the end, they would be fighting present Thanos again. I can't say for sure that that would have been a better movie... I'm no writer. It's just that there's always so much extra complexity when you have
time travel that they probably could have done without.
So anyway... I'm planning on seeing it again next week. I think the last time I saw a movie twice in theaters was Return of the King. It's not something I do generally. But I really feel that this film needs a second watching. There is just so much there. I'm actually not sure whether I liked it more than Infinity War or not, but considering that Infinity War was one of the 10 best movies I saw last year, that's a lot to live up to.