Potentially? They already have. Now they’re just linking things because they’re wanting easier and convenient access as well as “terms of service” clarity.

I think it’s safe to say google etc don’t require cookies to track you. And they’ve already mapped out any secondary gmail accounts you have. And they have your complete browser history joined from all devices they’ve stitched into your shadow profile which you can’t delete or access. Incognito mode is only good for the little spy guy graphic.

This is the 21st century - all activity is logged for future sale.