They didn’t mention that—did they edit their comment?

Quick edit: everyone should also have a PiHole, mine hasn’t been touched in years and does a bang-up job at blocking any regular ads (ads that, like the commenter I’m replying to mentioned, aren’t hosted on the same server you’re viewing stuff on)

YouTube ads come from the same domain as their video streams, so DNS-based ad blocking like PiHole can’t work on them.