[shawnz]

#1: They would have to give a rationale for the change which actually makes sense. The privacy explanation does not make sense because the observational capabilities of the API are explicitly not being removed. Therefore there is no benefit to user's privacy as a result of the changes. The performance explanation also doesn't make sense if we look at the numbers that adblocker vendors have been publishing in response to these changes.

#2: In light of the backlash to the proposal they would have to actually consider not implementing the change or at least consider some alternative implementations. So far all they have done is say "we've heard your concerns, and we're just going to do it anyway". Many interesting ways have been proposed to achieve the same supposed benefits as what Google claims manifest v3 will provide. But they have not responded to any of those ideas and are blindly persisting with their proposed model with all its downsides. So why even act like this is some kind of open process which involves real developers?

#3: They would need to demonstrate that they are actually concerned about the ability of adblocker vendors to deliver good products. They could have created a transition window from the old API to the new API to see in practice how adblocker vendors choose to use it and what limitations they face. But they haven't done that, instead they announce they're killing the old API the same moment they introduce the new one. That to me demonstrates that they don't really care if it's sufficient for those vendors or not.