On Android, it's a bit complicated but you if you are experienced you can use termux and yt-dlp.

You can use yt-dlp from a desktop too.

For youtube on android you can use newpipe. It allows streaming as well as downloading.

If the only thing you are missing is youtube download ability, why not use one of the many options to do that from a handset? Newpipe or Spottube are on fdroid. https://invidious.io/ allows you to do it from a browser.