It is fair to compare speeds, I just think it's probably the wrong argument to focus on if you're trying to convince people of the value of a language. It's definitely a supporting point, but at the end of the day, most programs don't actually need to be blazingly fast, they just need to not be dog slow. Ease of writing (correct) code and even more importantly maintaining and debugging code are generally far more important factors in a languages success, and those are all areas that Rust excels in.

The problem with a purely speed focused argument is that it's always possible to cherry pick examples in both directions. You can find some piece of idiomatic Go code that just happens to be faster than the equivalent idiomatic Rust code and vice versa. The fact that it's undoubtedly much easier to find idiomatic Rust code that out performs most Go code (idiomatic or not) is a much harder argument to use to convince people. The Go proponents will just argue that the ease of understanding the Go code outweighs whatever speed gains Rust has. That's why I think it's important to also point out that Go might be easier to write small snippets of, but for any realistic program it's going to be harder to write and maintain, and it will be more prone to bugs.