Why are/were Stanley Lunch Box kits so popular?

I am a few years late to the game, but I came across a video of an individual who made a mini camping kitchen setup and the entire thing packed into a Stanley Lunch Box. I thought "wow! That's such a a cool an ingenious idea!" Then I saw the 35 recommended videos of other people doing the same thing.

The whole thing got me thinking, why Stanley lunch boxes specifically? There are far cheaper metal boxes, hell, even Ammon Cans seem like they'd be a cheaper and sturdier alternative. Why Stanley boxes?