IsLoggedIn

The anti-abuse measures don't convince me. The two most feasible ones (to me!) are the password manager use requirement and displaying a prompt - plenty of sites will just make the user accept the prompt, and plenty of users don't want password managers (that debate exists and both sides see their points of view as obvious, but that's not really relevant here except that they exist).

I'd prefer to see just a prompt for cookie storing in browsers. Preferably something small enough that I don't have to interact with it. No API. Lynx does it decently (prompts for cookie saving before loading the site). The issue with this is the sheer amount of times it'd have to be done (per website! or maybe there can be some defaults? but that could defeat the purpose) and that many sites ironically use cookies to save that the user chose to disallow non-necessary cookies to be saved by the site as per GDPR.

Given that this API intends to fight an already rampant cookie-spam abuse: Why not instead figure out how to determine the admin email of a given site and make the browser automatically send them one message per cookie used, so it floods their inbox? It wouldn't be productive but it would make me feel better. This paragraph is only half joking.