There is a lot of CC0 content on youtube that exists so you can download it, like stock video, sounds, background videos etc. How are we going to dowload those

There is a lot of CC0 content on youtube that exists so you can download it, like stock video, sounds, background videos etc. How are we going to dowload those now? Also couldn't the youtub-dl team claim that the whole "drm video download test" was a security test?