>the problem is that the Python community at large rather prefers their C bindings or nowadays Rust, sprinkle a bit of Python FFI on top, and call them "Python" libraries.

They are Python libraries. Don't make the mistake of screwing up the cause and effect here. C, Rust etc - those are the replaceable parts of the chain. There is an official C++ pytorch library and virtually nobody uses it for ML Research. People want to code in python and build those libraries so they can.