4th is Gentoo. 5th is Debian’s logo inverted, so I’m not sure if that’s supposed to be Debian or a derivative that I don’t know off hand because there are so many.

Pihole will only ever be able to block so much, because it works at the domain level. When ads are served from the same domain as the desired content, which I believe is the case for youtube, Pihole is ineffective.

Adblocking plugins aren’t limited by this and can filter the actual content and HTTP requests made by the browser.