I think you can turn off targeted advertising from Apple, although there’s still untargeted advertising. As a user you can choose to lock (almost) everything i

I think you can turn off targeted advertising from Apple, although there’s still untargeted advertising. As a user you can choose to lock (almost) everything in iCloud so that Apple can’t see it, but that comes with the trade-off that they can’t help you if you lose your access. It will be permanently gone.