Earlier quoted context omitted.
Personal (not work related opinion): This basically can’t happen with things like DMA and GDPR. DMA in particular means you can’t share data across “products” without explicit consent. So you could for example collect websites that don’t work for the purposes of improving Chrome, but not then share that with the Ads/Search orgs for personalisation or targeting, as far as I understand the legislation. Personal opinion…
The thing is that preventing "sharing" isn't sufficient. People who are concerned about privacy don't want any such data collected or stored in the first place, ever. The implicit "sharing" of my data with Google (or whatever company) is a problem in itself. Regardless of how "seriously" Google (or whatever company) takes it, for a lot of the data I don't want them to ever have it in the first place.
Exactly this. It doesn't matter that google doesn't "share" what they gather if they own so many conversion funnels from top to bottom anyway.