I think that the bare bones stdlib is a huge mistake in Rust. I would love to see that rectified. Unfortunately, approximately 5 other people share that view. The Rust community as a whole is very opposed to adding functionality to std.
I mean, the case against it is pretty strong. Many languages with maximalist standard libraries have tons of vestigial code that nobody uses because the ecosystem found better solutions. Yet that code has to be maintained in perpetuity.
The C++ standard library even has this problem for something as basic as formatting (iostreams), and now it has two solutions for the same problem.