[graemep]

> 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.