Apparently Ryu is slower on shorter numbers than the Rust standard library's implementation which uses Grisu/Dragon. It might be only due to the implementation though. https://www.reddit.com/r/rust/comments/93d045/fast_floattost...
Also it seems that Ryu prints some numbers in weird ways even though "nicer" representations exist: https://github.com/rust-lang/rust/issues/52811#issuecomment-...