Anything to read on this, like papers and stuff?

Honestly, it's been over a decade since I read anything about this, and it's honestly not even my area of expertise. But I did my undergrad in anthropology, so "your culture makes this real" is a pretty basic concept to me.

So I'm not sure where to direct you other than to say Ed Hall has some great commentary on how your culture is below your own awareness, which kinda points you in the right direction.

and the fact that it's a different type of product entirely

Yes, but the specific comment I was responding to wasn't talking about that, and it's not the typical discussion people are having when they say "X fast food tastes so much better in Y country." Hence pointing out the egg salad sandwich thing, because they're genuinely really awful.

The convenience stores here in Japan are such a great example, because the actual reason America doesn't have the same kind of convenience store is because our grocery stores fill that niche, and you can stop at a grocery store on the way home from work whenever you want.

Meanwhile in Japan, commuting by mass transit is essentially mandatory - you don't really get a choice, so there needs to be additional shopping options for people who don't live close to their train or bus stop.

Which isn't to say that teriyaki burgers are bad, but just, "Oh, it's differnt, so it's neat" isn't always a good way to look at things, because you're taking it out of its cultural context and treating it like something it isn't.

Which, sorry, still doesn't answer your question, but it's just that understanding another culture is a HUGE undertaking, and there's a reason anthropologists do participant observation - you can't really understand a culture until you participate in it.

So, to a tourist, that egg salad sandwich might be neat and fun, but as someone who has actually had to commute to and from work in Tokyo, man, absolutely fuck those godawful sandwiches.