Why YouTube Remix Channels Make Money Without Problem

Why do YouTube channels of popular music remix make money without problems without copyright and without copyright what and its partner? If i dont please help me i did not understand

Maybe they are monetized, but that does not mean that the channel owner is making money. You can use some songs but the copyright owner will place ads, not you. Check which artists allow it at the YouTube music library:
https://www.youtube.com/music_policies

Some artists share revenue. Some, like NoCopyrightSounds, allow you to place ads and keep the money.

Yea I think a lot of remix videos don't get as much traffic as you think. Original content is more key. Unless you are doing compilations.