Youtube copyright monetization

Hello, tried to look in forum and did not find few answers, for a long time I was wondering, how do people can run ads on compilations, music etc. For example music channels, "black beats", "blue paradise", "criminal tbilsi" etc. Uploads music videos everyday and in description they all just write

"This channel is created to promote magnificent songs, and as well, producers. Absolutely, NO COPYRIGHT INFRINGEMENT INTENDED. This CHANNEL CLAIMS NO RIGHTS OR OWNERSHIP over the contents posted….

Youtube copyright monetization