You're picking a rather particular example. Most people don't live within 15 miles of an Amazon distribution center. To pick my particular example for contrast, I'm also relatively close to an Amazon facility, but it's still over an hour away by car. And I imagine that, for most people who drive to get around, the nearest big box store is close to their route home from work.

There's also an unstated major premise that packages never come from any further away than the nearest Amazon distribution facility. I suspect that the truth is rather far from that. It at least isn't true for me - I kept an eye on my Prime orders from last year, and 1/3 - 1/2 of the things I ordered originated from a more distant Amazon warehouse, and getting it to me within 2 days involved burning a whole mess of jet fuel. I suspect that the GHG emissions from doing that end up being a massive portion of Amazon's overall pollution.