What about food production? With half the population gone, there wouldn't be extra food laying around for the snapped-back people to eat. If food was snapped back too, it seems like the snapper has to think of a lot of details, on Earth and around the universe...
Caught this one late. My take on it is that when the people were "snapped back", it wasn't like they really were gone for 5 years. That if a person has god-like powers, the wish should not be "bring everyone that's been gone BACK", it would be "UNDO the original snap so they were never gone to begin with" (Banner indeed would have thought VERY carefully about this). Imagine the psychological damage to everyone who had died, coming back after 5 years, trying to deal with the nightmare way they saw themselves disintegrating, then instantly being back 5 years later, trying to adjust (with many of their family members probably having MOVED since then). A bit like what Ant-Man went thru after being stuck in time for 5 years, times a few billion on earth alone.
Of course one can quibble with the timeline effect and all that if the people were never gone, as a result, but it's a neater solution (there can't be a 100% neat solution, since even "restore everything to 5 years ago" means history would have gone differently for everyone on Earth in those 5 years, none of the grief and gloom and such).
And the Avengers still remembering the deaths after they were brought back is not necessarily a conflict to the idea people were brought back as though they never left (Star Trek would technobabble an excuse for that since the Avengers time traveled, they remembered the original timeline. Same as early in "First Contact" when the Borg went into the past to change Earth's history to turn it into a Borg world, but the crew of the Enterprise were not affected because they were still in a Tachyon field. Does not have to be a real thing, just "Hey, here's a sci-fi reason - believe this like you believe warp drive and transporters in this show").
Or if that doesn't do it, the snap also took care of the infrastructure being maintained. Which sounds like a lot, but not a lot to THINK about with such universal power. Any more than the snap involved THINKING of the 50% of all of the trillions and trillions of people/creatures in the universe would die, selecting one-by-one on an individual basis.
And oh yeah: Science-fiction bubble gum comic book movie series with extremely advanced or impossible technology, super powers, mystical/magic powers, aliens, god-like power stones, and a walking tree that only says three words (well, two other words in a three-word sentence, once).