The point I didn't make clearly enough is ad blockers probably wouldn't exist if others hadn't introduced this kind of feature through userscripts and add-ons.

The point I didn't make clearly enough is ad blockers probably wouldn't exist if others hadn't introduced this kind of feature through userscripts and add-ons. If only Apple can enable these abilities, it's up to other ecosystems to innovate and define access. In my opinion, the most important branch the Web could take right now is going from transparent content to opaque content. Now I can filter, transform, organize and augment content accessed through my browser, and even remix it, all enabled by the inherent organizing of the technology, which suggests to the larger society more can be done. It's an open question though, and that technology could be changed to restrict what can be done with content.