All of this adblock tech works on domain blocking for the most part. If they wanted to, they could host the ads on the first party server and most ad blocking

All of this adblock tech works on domain blocking for the most part. If they wanted to, they could host the ads on the first party server and most ad blocking wouldn't work anymore. They haven't yet, so it hasn't gotten to the point where they have been forced to. This adblock whining / detection lets publishers keep third party ad hosting and reduce adblock usage.