The rust compiler now has features that few or none C and C++ compilers have: incremental compilation within a single translation unit, pipelined compilation, multi-threaded and lazy query-based compilation, ...
Implementing each of these features have required whole program refactorings in a large-scale codebase performed by few individuals while hundreds of other developers where simultaneously evolving the software and implementing new features.
Having been a C++ programmer for over 10 years, none of these refactorings would have payed off in C++ because of how time consuming it would have been to track all bugs introduced by them.
Yet they do pay off in Rust because of my favourite Rust feature: the ability to refactor large-scale software without breaking anything: if a non-functional change compiles, "it works" for some definition of "works" that's much better than what most other languages give you (no memory unsafety, no data-races, no segfaults...).
Very few programming languages have this feature, and no low-level programming language except for Rust has it.
Software design is not an upfront-only task, and Rust let's you iterate on software design as you better understand the problem domain or the constraints and requirements change without having to rewrite things from scratch.
I think crater also deserves some credit here - given how much Rust source is in Cargo, it's very useful to be able to run a refactored compiler against all those packages and see which don't compile or start failing their unit tests.