~~I believe the request to the server is the same as if you were watching it. It just runs the file from their server to your browser, with yt-dlp it sends a request to the server file the same way a browser does. You can view the source code which is well commented if you are able to understand python. The function is in yt-dlp/downloader/http.py~~
After rereading the code, it’s not quite the same but I wouldn’t worry about the isp