It is difficult to see how it would be explicitly legal in any country that is a signatory to the Berne Convention and the three step test. Which is almost every functioning country in the world.
Personal use is allowed and nothing should be pay.
Only commercial use, need to pay for reuse, broadcast song.
This is a fair-use, blaming end-user people is so stupid.
Now Youtube, and all BIG one make a lot of money but are muscian more rich? NO, it's even more hard.
Are people still foled by major and music stolen by these compagny? Yes, welcome slavery 2.0
People that don't have money to fight now can just shut up against these big compagny even with small youtube channel you can see people stole video for each other, like the last one you get a kid stole another kid video after 2 days. He have stolen 40 videos, same content, same title, etc.
Do we agree to live in a such world, when you can't do something with value added? Sure we need to protect the right but in a same for every musician. Every musician should have the same right to protect their music but that's not the case.
Also I don't think we need to pay to give service. Example. I have a bar, people listen to some music ok, but why I need to pay? I make a free adversting of that music? It's not that enough? I don't earn money with that music, I earn it with the bar.
The same can apply with movie. We need movie that can come from another place that hollywood and there big industry of movie, they are all crap but sell because like pop music it's what generate revenue.
The European Union Copyright Directive explicitly allows member states to have legislation allowing copies for private uses. Germany for example makes use of that exception. It is allowed to make copies of copyrighted works for personal use (with some restrictions). In exchange we pay a special tax on storage media which goes to right holders (for example 36€ on a smartphone).
That topic is far away from my area of expertise but we had some high-profile court cases regarding private copies and if there had been any way to shut that down via the Berne Convention it would surely have been tried.
Copies for private use are as such not a gray area, but explicitly legal. I fail to see how a site that helps making those copies could be illegal in any way. There was a court fight in Germany over the backups the site was doing, but it is telling that it was only about that, not the core functionality, and that this current attack on peoples right was launched from an US court.