[olliej]

The privacy problems were catastrophic - the Google CDN fed directly into Google’s pervasive tracking infrastructure.

Most other CDNs similarly support tracking services.

As the article says the actual cost of partitioning is negligible, the cost of not partitioning is that nothing can prevent cross site tracking and invasion of privacy.

VPNs and extensions don’t work because the browser is ensuring your identity is constant. That’s why the large ad networks funded free/cheap CDNs.