I have this discussion with my 16 year old and find I have to look at things differently sometimes. Plenty of stuff that happens in the comics you can't do in the movies for a number of reasons (studio character rights, characters not introduced, storylines that wouldn't play in society today, storylines that have too much backstory/history/baggage, etc). So while part of me wants to play MC Disagree whenever a movie diverges from the comics (as I did with nearly every Spiderman movie), I understand a 16 year old today would have no concept or care for storylines and background of stories that reach back to the 70's. Even if you gave them the comics, they may not resonate with them for a variety of reasons.

You have to look at the MCU as it's own thing, with their version of the characters pulling from the comics, but not being exactly the same. Killing off a character in a comic and bringing them back via plot device/retcon is easy in the comics. In the movies? Harder to do from a practical standpoint (actors age, need contracts renegotiated, sequel and story needs to be greenlit, etc). In a comic you can change something in a few issues, i.e a few months. Can't do that with a multi million dollar movie and billion dollar franchises.

Since this is a 2 part movie, I can't say what deaths will stick and which ones won't (besides BP and Spidey). Cap and Tony may still die by the end of Avengers 4. We may get the meaningful deaths for the casual fan and the hardcore fan by time all is said and done