Lots and lots of people do web stuff in Python. There are a whole bunch of Python web frameworks like Django, Pylons, Flask, etc.

And there are big sites written in Python, too. Reddit, YouTube, some Google apps, Spotify, Netflix.

Rust is still a bit young, but also has several web frameworks like Rocket. No big case studies that I know of, but Rust still has many more fields of applications than PHP does.

Sure, a small minority of sites are partially written in python.

Tons of sites are written exclusively in Python. Django alone has 60k stars and 25k forks on Github. That about the same as Laravel.

A quick search came up with an order of magnitude more sites in laravel than django. And combined are still a small fraction of sites on the internet.

Whichever way you spin it, building web stuff is a perfectly normal thing to do with Python. Thousands of companies do so, even big famous brands like the aforementioned.

people aren't doing web stuff in python?? django, flask, etc. are still very popular. maybe not as much as a few years ago, but people tend to stick to tech they know well, and python's web libraries are pretty battle tested at this point.