Their experience, literally, was, "we tried to fix it and the whole Internet yelled at us".
I believe a practical (if oversimplified) model of the trade-offs is more like "secure, useful, fast: pick two".
FWIW, it's not surprising. I don't install extensions because I don't see how you can possibly trust arbitrary code published by a pseudo-anonymous screen-name to have unlimited access to all browsing activity. That proposal sounded great to me, it would have been nice to be able to use an ad blocker.
Is that true? I thought the proposal was to allow extensions to provide rules to be run on requests being made, but not to see the requests themselves. The same way Safari extensions apparently work?
No, the observation API is untouched[0]. It affected the ability of extensions to arbitrarily intercept and redirect requests, which (to be fair) is a potential MITM risk.
IF an extension relied on the declarative model and ignored the webRequest API, you would get a reasonable increase in privacy, because extensions wouldn't be able to monitor what requests had been made or whether or not they were really blocked.
But there were no plans to discourage developers from using the non-blocking parts of the webRequest API, so those advantages were pure speculation.
> The same way Safari extensions apparently work?
Yep. It's worth noting though that:
A) Safari hasn't removed the ability for extensions to use the non-declarative model.
B) Safari's approach does have documented downsides that make adblockers using their new strategy objectively less powerful. Adblock has a decent page up describing their take on the tradeoffs between the two approaches[1], and you can find similar conversations surrounding other Safari blockers if you poke around long enough.
[0]: https://docs.google.com/document/d/1nPu6Wy4LWR66EFLeYInl3Nzz...
[1]: https://help.getadblock.com/support/solutions/articles/60000...
Most of the Internet probably never even heard about it.