Ultimately, it’s a good thing for Far From Home to address the Snap.
I don’t expect Far From Home to dig too deeply into it, but an explanation would certainly be helpful and serve as a great way to show how this universe is moving post in a post-Endgame world.
Marvel likes the high school setting for Spider-Man and it makes sense that it’d want to keep him there for as long as possible.
It helps to explain how the world works now that Thanos has come and gone, and it sets the status quo for Peter moving forward.