I think, it is very important, that people started to actually discuss and compare different approaches to safety, instead of just saying that since Rust is safer, we should throw out all of c/c++ code and rewrite everything in rust.
Deeply embedded code doesn't use malloc, doesn't use threading.
I could use a better type system, ala Ada, being able to say "this variable is of type distance in meters, this variable is of type time in milliseconds", that'd have cut the # of bugs by a huge amount.
But simple, unsexy, type system changes like that aren't what language designers are focused on.
Who here has never confused Milliseconds and Seconds when passing a variable around? Trivial for a compiler to catch with a half decent type system, but few modern languages bother to try.
Even when writing modern code in newer languages, I rarely directly use threads, and if I need to pass data between them 95% of the time I can get away just doing a deep copy to avoid the hassles of sharing data between threads!
Obviously Rust is meant solving different problems than the ones I face, I have friends who frequently write highly threaded code, but in my day to day, Rust doesn't offer much more safety.
(However, Zig does look super cool and interesting!)
I think the biggest thing was that university curriculums and mainstream app development platforms (like Microsoft) stopped pushing it as hard when the level of horror got past a certain point. It used to be pretty bad. Business apps being written using MS "Active Template Library" in C++ and then used as signed ActiveX plugins on IE6-only web pages etc.
Though I believe there were some languages with features to that end, at least research languages, they weren't that well represented. I think Rust's presence brought attention to the possibilities there, and an increasing number of people see the value of investigating and developing that niche.
So basically you have the DevTools and Azure teams pushing for .NET, Java and other safer languages, while Azure Sphere has a C only SDK and WinUI/UWP push C++ above anything else, with some C++ only APIs.
Politics.