[feanaro]

The question still remains: what are they optimizing for if we already have sub-millisecond response times?

The only evidence you offer is anecdotal. I'm having a hard time imagining perceptible differences in sub-millisecond response times so either you or the study are in error.

And just to reiterate other comments: yes, Safari is probably able to block ads just fine now, because they modeled the engine according to capabilities needed right now. However, it comes at a huge cost to innovation and creates yet another barrier of entry guarded by a large corporation.

Taking all of that in account, it seems unnecessary. The looming threat of ulterior motives from Google remains ever-present.

[saagarjha]

To be honest, I'm much more in favor of this API because of its privacy features than performance. I think it's a little bit faster, but it has a much bigger benefit on the trust side because extensions no longer run arbitrary JavaScript in every page I visit.

[feanaro]

It's very improbable the few popular ad blocking extensions could slide in something sinister and avoid public scrutiny for a long time. You have much more reason to be worried about your privacy from Chrome than from uBlock Origin, since Chrome and Google provably violate it.

[saagarjha]

I don’t use Chrome partially for this reason :)

[ubercow13]

It does not have any privacy benefit. Extensions can still do that

[saagarjha]

They can, but presumably they will be clearly labeled as they are today.