Web developer here. A “cookie” is just a piece of information stored on your machine. A cookie can be a setting, saved app data, or a tracking id.

The reason you keep seeing the banner is because by saying “no” to cookies, you’re telling them they don’t have permission to store ANYTHING on your computer. Which is fine. Your computer your call.

But if they can’t store anything on your computer, there’s no way to remember that setting next time you come to the website. No local setting storage means they don’t have the stored “no cookies” setting to load. Likewise there’s no tracking id they could potentially look your setting up in their own database by.

Web site requests are “stateless”. That means that, to a web server, each and every single request to a server is its own brand new, separate connection with no link to any other connection. The only way to share data between individual requests is via some kind of stored “state”. That state can come from your computer in the form of cookies, or from the server in the form of sessions. But linking a connection to a session requires your computer providing a session id; and guess how your computer has to store a session id? If you guessed “in a cookie” you win.

Are cookie popups annoying? Oh holy Christ yes, both from a web user standpoint and from the stand point of having to implement them as a developer. But by outright rejecting cookies (and/or auto-wiping your cache/cookies when you close the browser), you’re telling the website it’s not allowed to store your preferences for not having cookies and eliminating the websites ability to recall that preference at all.