It seems like enough people find their way around them. Refinement might make them easier for people like me with less experience navigating language documentation, but that might come at the expense of developing the language. Priorities are important. Especially since Rust doesn't have Google's resources.
the fmt docs are... not ideal. That said, there's a lot there, and it's all useful, but it's just tough. Frankly, I just punted on improving them, and haven't taken the time to do so in the years since.