I don’t know how or why you see ads on YouTube. I have been using firefox and before that whatever else, for a very long time. I have not seen an ad of any kind on YouTube in many MANY years. And since sponsor block came out I’ve only seen a few that managed to slip through. I just fast forward. But why would anyone suffer YouTube with ads? You’re volunteering for it at this point because it’s insanely easy to block them.