It’s not a single layer, it is designed the same way apples service runs. This is addressed in the article.
> We are considering using 2 hops for improved privacy. A second proxy would be run by an external CDN, while Google runs the first hop. This ensures that neither proxy can see both the client IP address and the destination.
— https://github.com/GoogleChrome/ip-protection#core-requireme...
If they choose to go ahead with the second hop it would be the same as Apple’s approach. But it sounds like this has not been committed to yet.