Lack of types, lack of static analysis, lack of ... well, lack of everything Python doesn't provide and fights users on costs too much developer time. It is a net negative to continue pouring time and money into anything Python-based.
The sole exclusion I've seen to my social circle is those working at companies that don't directly do ML, but provide drivers/hardware/supporting software to ML people in academia, and have to try to fix their cursed shit for them.
Also, fwiw, there is no reason why Triton is Python. I dislike Triton for a lot of reasons, but its just a matmul kernel DSL, there is nothing inherent in it that has to be, or benefits from, being Python.... it takes DSL in, outputs shader text out, then has the vendor's API run it (ie, CUDA, ROCm, etc). It, too, would benefit from becoming Rust.
I wish this were broadly true.
But there's too much legacy Python sunk cost for most people though. Just so much inertia behind Python for people to abandon it and try to rebuild an extensive history of ML tooling.
I think ML will fade away from Python eventually but right now it's still everywhere.
To say most ML people are using Rust and C couldn’t be further from the truth