> It is theoretically possible, given enough work, run Python directly in Wasm.

To be fair that's not just theoretical, the Pyodide project does exactly that:

https://pyodide.org/en/stable/

There have been several ports of Python to JS or to wasm over the years. Pyodide is the most mature today, but another interesting one is pypy.js which ported PyPy and even included a JIT!

But I agree that CheerpX allows running more things. There will always be a use case for "just run an x86 binary" when you don't have the source code. But for things where the source is available a proper port to wasm like Pyodide will be faster.