The problem is that I cannot count on being able to install new software in many environments.
If I fight the battle to get centralized IT to install Python, I now have a guaranteed set of standard libraries as well. I'm never going to get permission to install anything other than default. Ever.
Consequently, the standard libraries need to be very complete and very useful.
And, while people seem to love the Rust approach to libraries, I'm not necessarily a fan. Far too many times I have pulled a library that is "obviously" something that a language should consider to be "standard library" and gotten bitten because it was broken. Only VERY core libraries in Rust are guaranteed to work across multiple architectures and OS's.
I think Rust is probably doing the right thing for Rust as "batteries included" is NOT one of its tenets. However, that doesn't make it right for everybody else.