> But store meals required purchasing food in larger quantities than necessary (think a 12-pack of hamburger buns for a two-person meal).

This is the key, and one of the reasons I love Blue Apron. The meals come in such exactly portioned amounts that the only thing left when I'm done eating is the packaging. There is zero food waste, ever. (Incidentally, this makes an effective weight-loss diet if your problem is overeating like me.)

That being said, I wonder if Blue Apron would still come out ahead of home cooking if you did not attempt to make the same meals but instead more typical home cooked meals. Blue Apron recipes on average are more varied and have more ingredients than what a person would normally cook, so I wonder if the extra food waste is more a consequence of trying to reproduce them.