The mall and video games
"Present day" in the series is about 20 years after the collapse and bombings.
So, if Riley is "16 almost 17" she would have been born 3 to 4 years after the collapse.
Ellie is 14 and she was born 5 to 6 years after the collapse and bombings.
Neither one of them would have known what a mall was if they grew up being told they were "sealed up."
Neither one of them would have known what video games were, how to play them, how the knobs, buttons and joysticks worked, and what money was used to get them into "play" mode.
I know that fiction requires a little suspension of disbelief, but their nostalgic excitement in the arcade was totally misplaced.