No. People won't write C extensions. They will write something heavy like Redux (which recreates full object graph on every event) in Python.
We added support for PyScript using Collagraph, which allows you to define single file components with a Vue-like syntax.
Excerpt from the project README:
Write your Python interfaces in a declarative manner with plain render functions, component classes or even single-file components using Vue-like syntax, but with Python!
- Reactivity (made possible by leveraging observ)
- Function components
- Class components with local state and life-cycle methods/hooks
-Single-file components with Vue-like syntax (.cgx files)
- Custom renderers (PySide, pygfx and now PyScript)