Also to point out, you can 100% leak memory in safe rust
"Can" is the whole thing. A rust dev risking can is like a C++ dev risking can.
I like rust and do what you want in personal projects, but introducing it to a GC space when there are langauges that "can't" be unsafe is irresponsible when a GC language can offer all the upside of rust.
GCs prevent memory leaks, which safe rust can do. So even if you somehow make sure no unsafe is ever used, you can still introduce a hard to debug issue just because you want to use rust.
It's also worth pointing out that most GC languages can have the same issues as a Rust program (if not more) just by virtue of having FFI. In Python, I can quite happily load a C extension and ignore all the rules. Whereas in Rust, if I want to use a C library, I still need to explicitly declare it as unsafe code.
In practice, I tend to find that I have to think more about how I approach parallel/multi-threaded code in Rust than I do in other languages - not because it's dangerous, but because the compiler doesn't allow code that would break memory safety guarantees. In some ways, that's obviously a bad thing if I'm having to think more, but in my experience, the thoughts often lead to a better design anyway. So in the end, I'm more confident in my Rust code than I am in equivalent code in a GC language.
Many memory safety violations have been discovered in rust crates: https://www.infoq.com/news/2021/11/rudra-rust-safety/
Maybe I wrong on that, but if it can’t guarantee crate safety, then it doesn’t really do anything.
They're not the same because how C++ does memory safety and how Rust does it is unequivocal. C++ is unsafe by default, Rust is not, and you are ensured it is not, as I mentioned, via things like the borrow checker. To equivocate them is to fall into the same trap you yourself mention.
There are no GC vs non-GC spaces. The point of Rust is to be able to have memory safety without a garbage collector, that's literally why it was made. Thus, it is expected based on that premise that we be able to use Rust wherever a GC could be used. The fact that unsafe exists does matter, as long as unsafe isn't used. I too can turn a GC language like Java into an unsafe monstrosity, by for example doing raw bytecode tinkering, does that mean that Java is now unsafe? No, unsafe is merely an escape hatch.
Rust comes with additional risk. It is easier to leak memory, it is easier to be unsafe (especially since you can't guarantee what future other devs will do), but you gain nothing.
You get all that risk, but fearless concurrency can be done in GC languages (like Elixir) and many people have created the Result type before. So you have added risk for no benefit. Not to mention its easier to hire devs (and train devs) for other GC languages cause not everyone knows or understands the borrow checker.
Is there any advantage?