Python with it's C API basically gives you the keys to the kingdom on a machine code level. Modifying something that has an API to connect to essentially anything is not an easy proposition. Of course, it has the advantage that you can make Python faster by performance analysis and moving the expensive parts to optimized C code, if you have the resources.
They test it against the top 500 modules on PyPI and it's currently compatible with about half:
https://www.graalvm.org/python/compatibility/
But investment continues. It has some other neat features too like sandboxing and the ability to make single-binary programs.
The GraalPython guys are working on the HPy effort as well, which is an attempt to give Python a properly specified and engine-neutral extension API.
What I would've preferred is they leave all that stuff alone, add nice features like async/await that don't break existing things, and make important changes to the runtime and package manager. Python's packaging is so broken that it's almost mandatory to have a Dockerfile nowadays, while in JS that's not an issue
There are a lot of faster python runtimes out there. Both Google and Instagram/Meta have done a lot of work on this, mostly to solve internal problems they've been having with python performance. Microsoft has also done work on parallel python. There's PyPy and Pythran and no doubt several others. However none of these attempts have managed to be 100% compatible with the current CPython (and more importantly the CPython C API), so they haven't been considered as replacements.
JavaScript had the huge advantage that there was very little mission critical legacy JavaScript code around they had to take into consideration, and no C libraries that they had to stay compatible with. Meaning that modern JavaScript runtime teams could more or less start from scratch. Also the JavaScript world at the time were a lot more OK with different JavaScript runtimes not being 100% compatible with each other. If you 'just' want a faster python runtime that supports most of python and many existing libraries, but are OK with having to rewrite some your existing python code or third party libraries to make it work on that runtime, then there are several to choose from.