A neat tool, but YouTube is generally an abysmal source for music. That's partly deliberate (from record labels) and partly an inevitable consequence of recompression with different lossy formats.
Unless something is completely unavailable elsewhere, you'll find far better audio quality from other (original) sources.
It's not so much about availability or even quality as it is convenience for a lot of us. Soviet funk here, favorite TV news theme there, C64 remixes over here, NPR tiny desk over this way, and a rendition of the full original vocal lyrics to the M:I theme which is basically only available on YT itself...
I can't imagine trying to source this stuff independently and keeping up with it, and if some commercial music crept in I imagine it'd be easier to simply stay on YT and ask what level of quality one subjectively needs for dental drilling, or mindless work, or throne-in-lair-sitting, or whatever it is...
> Unless something is completely unavailable elsewhere
I do run into this from time to time. Let's say I want the soundtrack to one of my favourite anime, from 2006.
Some items from it are also on the source game soundtrack, so are available on iTunes. This is actually kind of rare for older anime which usually don't bother releasing in iTunes outside Japan, but being a game adaptation helps it here, I guess. Still, anything composed for the anime are not included.
Some of it is there on Spotify. Actually, at one point it all was, and I can still see the tracks are there but grayed out in other people's playlists, so I assume there exists some region in which it was available, and the availability in my region initially was a mistake by a licensee who forgot to limit it to the regions they had rights for. Either way, it's no longer legally available for me.
So I could.... VPN to Japanese iTunes, thereby breaking the terms of service, (assuming it's still there) or I could try import some decade old special edition DVDs of the anime which contained the OST.
Or I could rip it from YouTube. Eventually, if you make no effort to sell to me, I'm going to resort to other options.
> So I could.... VPN to Japanese iTunes, thereby breaking the terms of service...
In my experience, you'd immediately enter "vacation mode", which is limited to two weeks in free version, but unlimited in premium. Spotify doesn't even complain when you switch countries in a couple of seconds. They're very lenient on enforcement, I've used it for like five years before Spotify actually became available in my country (though I couldn't pay for the premium with a card from a different country). Just log in via VPN once, then it works for two weeks.
YouTube has a ton of obscure music that can’t be found on Spotify, plus things like old TV specials, theme tunes, outtakes and the like.
The quality is usually pretty bad, it’s true. But in many cases, this stuff is almost impossible to buy even if you wanted to, so YouTube is your only option.
YT is also fairly unpleasant to use, which is why a lot of people go for youtube-dl.
That and a lot of music I have found on there has a music video version of the song which can sometimes be slightly different than the original song. It's usually something like a longer intro before the music starts or something like cheering from a crowd or whatever to mimic it being a live performance music video. So you're getting a subpar sound quality combined with a sometimes differing song from the original.
Unless something is completely unavailable elsewhere, you'll find far better audio quality from other (original) sources.