Yeah, it's like people who spend time around campfires and have watched American media are all going "let's make s'mores" [1], and then they realize that "graham crackers" [2] are a mystery ingredient that nobody knows anything about.
Digestives [3] are the typical substitution in my experience, but again nobody knows how close they're getting. They look thicker, to me ...
[1]: https://en.wikipedia.org/wiki/S%27more