On a random electro-swing video I get the following choices in youtube-dl:

audio only DASH audio 53k , opus @ 50k, 1.01MiB

audio only DASH audio 69k , opus @ 70k, 1.34MiB

audio only DASH audio 130k , m4a_dash container, mp4a.40.2@128k, 2.63MiB

audio only DASH audio 136k , vorbis@128k, 2.59MiB

audio only DASH audio 140k , opus @160k, 2.69MiB

Seems pretty decent to me.

Yes, I'm actually quite impressed that they offer opus @160k. The real issue with Youtube is that you never know what the source was. If they're reencoding that from a 128 kbps mp3, that suddenly becomes much less impressive.