Well, it shouldn't be a surprise to anyone that there's many use cases out there where you just have no other choice but to use a lower-level language (where, unfortunately or not, the common tool of choice these days is still C/C++) since the application/library is either dealing with too much data or has to be very responsive, or both. Since this thread is about Python, some good well-known examples would be libraries like numpy/pandas; but there's also some like polars that are written in Rust.

Re: your point, I'd still recommend learning Rust even if it's just solving last year's AoC, to see how various data structures, enums, traits, iterators etc work. Even if you don't end up using Rust on daily basis, it will probably affect the way you structure non-Rust code and provide you with a few neat design ideas.