I saw a talk by someone from Google about their experiences using Rust in the Android team. Two points stuck out: they migrated many projects from Python, so performance can't have been that much of a concern, and in their surveys the features people liked most were basics like pattern matching and ADTs. My conclusion is that for a lot of tasks the benefit from Rust came from ML cicra 1990, not lifetimes etc. I feel if OCaml had got its act together around about 2010 with multicore and a few other annoyances[1] it could have been Rust. Unfortunately it fell into the gap between what academia could justify working on and what industry was willing to do.

[1]: Practically speaking, the 31-bit Ints are annoying if you're trying to do any bit bashing, but aesthetically the double semicolons are an abomination and irk me far more.