It's actually already broken. If you try to download more than 3-16 videos (the limit is not clear), you start to be rate limited to 300 kbps or so. According to Reddit this is fixed in a fork called yt-dlp

To be honest that sounds fine. You're presumably downloading it to watch it offline, the download speed isn't really material as long as it finishes eventually

youtube-dl is also used by video players like mpv for live streaming. In this case, 70 kbps is completely unusable for the vast majority of videos.

One other workaround is to use '-F' to get a list of formats, and choose one of the non-default formats to download. This seems to work for me.

Primary function, perhaps, but it's used for lots of websites that aren't YouTube, and some of those websites have broken.

There are open pull requests and/or bugs for many websites that aren't being approved. This is rather unusual for youtube-dl, it normally had a release ever two weeks or so.

It may say “YouTube” in the name, but it’s a tool designed to work with many sites.