Cookies and fingerprinting tell me that the same browser is coming back to my website, but I don't care about the browser I care about the user. As a user if I

Cookies and fingerprinting tell me that the same browser is coming back to my website, but I don't care about the browser I care about the user. As a user if I go to a website on my work machine, my home machine, and my phone then I'd like my data to be available on each. I don't have strong opinions on OAuth or any other federated identity solution, I just think it's a specious claim to say that just because a system doesn't care about who a user is then that system doesn't care about the uniqueness of that user.