[dullgiulio]

I am not sure it is a good idea to trust the server to decide what is more important. I can easily imagine ads taking higher priority than actual content, just look at the pop-ups that interrupt reading.

Browsers and protocol should start concentrating on how to secure users from the very sites they visit.

[pornel]

Prioritization works within a single HTTP/2 connection. Ads are generally served by a 3rd party, and while there are some limited ways of sharing HTTP/2 connections across origins, I don't think any ad servers offer such a close integration.

Besides, sites already have blunt tools they can use if they really wanted to force ads to load first. This feature is more for site developers who care about performance. Instead of tweaking the markup and adding hints to help browsers request resources in the right order, they can now set the priorities directly and precisely.