...In case, as a compromise, one could always set the video rate at 144 rows - taking roughly one twentieth (to even one thirtieth) of the bandwidth of a 720 rows - from the original YT interface.

(Video at 144p can take as little as 2 kilobytes/second to download (for more static content); typical 720p can easily take 100 kilobytes/second. You can see those values using "-F / --list-formats" on the downloader command.)

But surely there is also the ability to stream good ("-f 140", ~128kbit/s m4a) audio piping from downloaders.