If the avg man knew the concept of an adblocker we would live in a different online world. I've seen people sit and watch 2 minute ads and or complain about how cramped pages are, they know they don't want ads and it's annoying but only a small percentage of that google "block youtube ads" and can click their way to install an extension etc.

Is it possible on iOS as well?

The ios youtube app seems to bypass the ad blockers, I stream on ios using brave it blocks youtube ads for me.

There is a Safari extension for this. With the added advantage of replacing the stupid YouTube player with standard video controls.

https://andadinosaur.com/launch-vinegar

Maybe they want the music clips for offline viewing?

Indeed. If the industry won't give me a simple way to purchase a file, I'll make my own.

That's my case - as I know that some music videos/clips will disappear soon or later for any reason (happened in the past), and as I cannot buy+download them then the only option I'm currently aware of is to download them with youtube-dl. It works reliably and it's simple to use.

In my case this often happens "in addition" to buying+downloading the song's mp3 (usually on Amazon).

I'm downloading them so I can listen without being randomly paused by youtube. Also ends up saving bandwidth massively, and mpv --no-video wastes far less cpu than firefox.