[jsnell]

Topics is going to be far easier to block with an extension, or to have an extension provide fake data for, than 3rd party cookies ever were.

Blocking 3rd party cookies always had a big risk of breaking stuff, since they could be used for legitimate purposes too, not just ad tracking and have built up a couple of decades worth of those legacy use cases. Topics is a tightly constrained single-purpose feature. Nothing will break when it's turned off or blocked.

But also, it's not like there's much reason to use an extension to block Topics, given it's an opt-in feature (unlike 3p cookies which were opt-out) and can be turned off at any time from the settings faster than installing an extension would be.

> Finally, your steps only tell me what Google is telling others. It tells me nothing about what data the browser itself might be collecting and passing onto Google.

That's totally independent of Topics though.