I imagine that in addition to having more packages, it is easier to hire developers who know Python than who know Rust. Current tiobe index puts Python at #3 (rating=10.86%) and Rust at #30 (rating=0.49%). If you already have a team experienced in Rust, then it may be a good choice, but if you are expecting to grow your team, you may want to pick a language based on popularity.

Language-wise, it feels like they are intended to solve different problems, so Python vs Rust is a weird comparison. Granted, that may because I started learning Rust as a replacement for C++, so that has been my point of comparison.