[deleted] It has no access other than to things you will allow it to have access to.
This is true, in theory, but my question or thoughts are on how true this actually is in practice, specifically in the case of Joe.
For someone with a deeper understanding of Android, that statement makes sense. To someone with less knowledge, I think it implies they have a direct, completely transparent choice in either giving or not giving that access. I don't think that's the case.
Most people aren't aware that just by installing one app, they could be consenting to sharing sensitive, personal information with another app whether that be Google Play Services or Subway Surfer, sandboxed or not. That's largely determined by the permissions granted to each app, sure, but also largely what the apps themselves choose to do, within what they can do.
Also quoting official documentation here, "profiles are the only way to provide a strong assurance of separate identities since the application model of the OS is designed to support communication between apps within the same profile, but never between them".
"It has no access other than to things you will allow it to have access to" implies to the layman that Google will only know that throwaway@gmail.com downloaded Signal, Facebook, and Netflix.
In reality, Google could easily know that throwaway@gmail.com is signed in on the same profile as Joe Schmoe on Facebook, who's linked to joeshmoe@gmail.com, and suddenly the loss of Google Pay, Android Auto, and Joe's banking app is less justifiable.