I thought the ending was quite weak, to believe all these characters are dead? Dr. Strange basically made each of his dialogue a Chekov's gun level of setup, "if it's between saving you or the stone I won't hesitate to let you die", "I saw 14 million possible outcomes and only one where we won", "It was the only way", or when Ebony Maw tries to take the stones and he says there's magic around it. All this dialogue isn't exactly the same, but you can guarantee that everything that happened AFTER Thanos takes the time stone will be undone.
The deaths of Spiderman and everyone I just didn't take seriously and was disappointed by, it's so obvious it'll be undone, but also it didn't really linger to let you feel the emotional weight of each character disappearing into the wind. They also didn't do justice to a lot of characters. It was very fun, and didn't feel long at all, Maw and Thanos were perfect, Thor was perfect...ish. But there were so many areas that could have been better.
Black Widow should have died, she was stupidly overpowered. Banner is a bumbling idiot now, made to seem dumb and incapable, wtf. Cap had nothing, just appeared behind a speeding train magically, wasted I feel. Proxima Midnight a wasted character, made to look weak. Corvius Glave, underused and not very good. Wanda looked weak compared to her usual power levels. Thor should have used his powers before getting the hammer.
It's a shame because there were so many great things in it, I just don't think it was as good as it could have been... yet I'm still excited to watch it again!