If you're generally supportive of the previous 19 moofies. . . yeah.
The ending is contrived because we know it'll be reversed somehow.
Don't even bother seeing it if you haven't seen Thor: Ragnarok, Dr. Strange, Both Guardians Movies, both previous Avengers movies and Captain America: Civil War.
I disagree. If you have a general concept of the characters and have not seen every movie, you can enjoy it still. Just brush up on the plots online. Wife and I didn't see Dr. Strange or Civil War and we still were able to follow.
From a non-comic follower's perspective, the movie itself is amusing. Some decent one-liners. But yes, the ending was meh and it's predecessor is very predictable.
Interested to hear what FP and others think.