> But in go you can just _err and never touch it.

You can do that in Rust too. This code doesn't warn:

    let _ = File::create("foo.txt");

(though if you want code that uses the File struct returned from the happy path of File::create, you can't do that without writing code that deals somehow with the possibility of the create() call failing, whether it is a panic, propagating the error upwards, or actual error handling code. Still, if you're just calling create() for side effects, ignoring the error is this easy.)