Plenty of C++ practitioners who still intend to mostly write C++ after learning some Rust said it actually gave them useful insights they'll be applying in future C++

We can also see in the committee proposal papers "Rust does X" has for years now been a good comeback when you need to show that X is a realistic choice not just for languages like Python which may be less concerned about performance and incur a heavy runtime, a garbage collector, etc., but also a "real" language like C++. The paper which landed code.contains("FOO") in the C++ string handling code is an example, there's a long list of languages which do this but they made sure to mention Rust.