It would be very difficult indeed to make it impossible to implement CGI scripts in Python; you'd have to remove its ability to either read environment variables or perform stdio, crippling it for many other purposes, so I didn't think they had done that. Even if they removed the whole http package, you could just copy its contents into your codebase. It's not about making Python less powerful.

As a side note, though, CGIHTTPRequestHandler is for launching CGI programs (perhaps written in Rust) from a Python web server, not for writing CGI programs in Python, which is what the cgi module is for. And CGIHTTPRequestHandler is slated for removal in Python 3.15.

The problem is gratuitous changes that break existing code, so you have to debug your code base and fix the new problems introduced by each new Python release. It's usually fairly straightforward and quick, but it means you can't ship the code to someone who has Python installed but doesn't know it (they're dependent on you for continued fixes), and you can't count on being able to run code you wrote yourself on an earlier Python version without a half-hour interruption to fix it. Which may break it on the older Python version.