I'm a Rust convert, but that needs to be put into context: I do stuff in in cryptography, often on embedded. Prior to Rust I did C and C++ for most of my work. There's also Ada... and it has SPARK, but Ada has never had the level of exposure that Rust has achieved.

But there's all manner of "business systems", e.g. Java/RHEL shops, ".net shops", where GC pauses don't matter, the code is something other than CPU/memory bound anyway,the GC/JIT are mature, and a human writing C++ likely can't do better and will probably do worse. I've seen this with a write-heavy log-ingesting system where the developers used smart pointers everywhere - which internally use atomic reference counting, which implies sync barriers for otherwise entirely unrelated data. I agree, these kinds of places are unlikely to move to Rust - the code writes faster in anything else and runs well. There's also Go, which has a GC but compiles natively, GraalVM, which is AOT compiled Java etc. I definitely agree GC'd languages are not going anywhere.

I'm not sure I agree with C# becoming more important because of ARM, though. I don't think it'll change much - I think shops already invested in certain stacks will mostly stick to them and for all Rust's popularity, it doesn't make sense to implement your CRM in it really. It does, however, make sense to reimplement the C++ parts of the .net runtime and miscellaneous other C and C++ parts of Windows that can benefit from the borrow checker, because it vastly reduces spatial memory safety bugs. There's a massive cost to this, but it's no longer just about about on-prem patching but Azure.