The latest version of iOS (14.5) introduced App Tracking Transparency, a new set of dialog boxes that informs the user whenever an app wants to track their activity across the UI and that they can prevent this if they wish. According to new research, its uptake skyrocketed to 88% worldwide, and 96% in the US, within 1 week of the update's release.
https://www.notebookcheck.net/96-of-iOS-users-in-the-US-turned-app-tracking-off-after-the-14-5-update.538088.0.html
Too bad I can't see Google implementing something like this. And even if they did, it would only be a small piece of the privacy puzzle and they would just exempt themselves, which I wonder if Apple has done that.