That's not true: idiomatic Rust projects use `unsafe` much more liberally than other languages use FFI, because of shared xor mutable. That's not a knock on Rust. I couldn't be less interested in Rust vs. Go; I use both and would use them both in different situations.
I'm not saying it isn't reasonable, just that it serves a different role in Rust than unsafe/JNI would in Java: there are things you naturally want to express in Rust, not having anything directly to do with interfacing with external code, that want `unsafe` in order to (carefully) bypass shared xor mutable.
I doubt that "idiomatic Rust projects use unsafe liberally". It is a more liberal construct, perhaps, but IMO actual usage is usually reasonable. Unless you mean the standard libary's use of unsafe?