[simonw]

The GIL means you only get to use a single core for your code that's written in Python, but that limit doesn't hold for parts that use C extensions which release the GIL - and there are a lot of those.

The GIL is also on the way out: Python 3.13 already shipped the first builds of "free threading" Python and 3.14 and onwards will continue to make progress on that front: https://docs.python.org/3/howto/free-threading-python.html

And honestly, a Python web app running on a single core is still likely good for hundreds or even thousands of requests a second. The vast majority of web apps get a fraction of that.