My gut feeling is that this would be somewhat useful yes at shielding privacy. But even if you delete cookies every day, at least for me, that's a day of various advertisers tracking my motions across the web. And it also involves the inconvenience of losing the sign in cookies that are greatly convenient for me to have. For my own sake, I'd prefer not accepting unnecessary cookies.

On a macro sense, I also feel like there's a virtue to making it clear to sites that no I don't want their unnecessary cookies. Exercising my right to opt out (actually I'm American I have no such rights in my state) is a clear & direct signal, one that I hope someday perhaps the majority of the world might exercise. At which point there's little value in keeping up this user-hostile practice. Just deleting my cookies does reduce their usefulness, but it's not as clear a sign; it could just as well be someone who doesn't have a secure personal device they can rely on. I'd rather make it clear that no, I'm explicitly rejecting the premise of your cookies.

> My gut feeling is that this would be somewhat useful yes at shielding privacy. But even if you delete cookies every day, at least for me, that's a day of various advertisers tracking my motions across the web.

Browsers mostly block third part cookies by default or have an option to let you do so, so its only site's own cookies that need to be deleted.

> On a macro sense, I also feel like there's a virtue to making it clear to sites that no I don't want their unnecessary cookies.

That gives them an incentive to find ways to track you, such as fingerprinting. Limited data might convince them that tracking data is of low value.