If you go to YouTube to watch a commercial (here is an example for Orangina https://www.youtube.com/watch?v=wrkUDm9pnIw), should the whole video be blocked? YouTube provide a video hosting service and they add commercials on top of that.
I find it unreasonable to demand that YouTube essentially remove content from within the video. That would just end back in the EU "protect-the-children"-Chat Control area of the debate. You could have uploaders mark their videos as containing marketing (and perhaps they do) but enforcement would still be difficult given the sheer volume of videos.