It goes beyond that. Many languages expect that you use types such as size_t or usize for things that are conceptually collection sizes, array offsets, and similar things. In some applications, it's common that the conceptual collection is larger than 2^32 while using relatively little memory. For example, you could have a sparse set of integers or a set of disjoint intervals in a universe of size 2^40. In a 64-bit environment, you can safely mix 64-bit types and idiomatic interfaces using size_t / usize. In a 32-bit environment, most things using those types (including the standard library) become footguns.

I work in bioinformatics. A couple of times a year I check if browsers finally support Memory64 by default. They don't, and I conclude that Wasm is still irrelevant to my work. I no longer remember how long I've been doing that. Cross-platform applications running in a browser would be convenient for many purposes, but the technology is not ready for that.