As the post points out, Python web frameworks have historically not prioritized improving the performance of serving static files, and that seems… fine?

If we assume that all projects have a finite amount of engineering effort available, then triaging is expected. The best practice for production web applications for decades has been to serve them from behind a reverse proxy. From there, it is usually fairly trivial to use path matching to serve static files from the reverse proxy itself, a tool that is much better suited to this purpose and can easily saturate any link you throw at it without breaking a sweat.

It seems perfectly reasonable for the maintainers of these web frameworks to defer improving the performance of static file serving indefinitely given this.