Cookies are a basic building blocks of websites. If you login to a legit website, there's a cookie in your browser for that.
The popup is, yes. But the legislation they are pretending to be compliant with isn't.
For basic session-level cookies that are essential to the operation of some sites, no legislation requires consent. The issues are third party tracking, long term use stalking, etc. But those that want to stalk you want you to believe that the legislation is against even session maintenance & similar cookies as well so you'll be against the legislation and not them. And that is apparently working on you and some others commenting in this thread.
Also, largely due to the same anti-anti-tracking voices making spurious claims of what would happen, some put the warning up not because they think they need to, but to avoid having to argue that they don't need to if a complaint is made.
But to be fair the stories I have heard were something along the lines of: a freelancer making a website for a local restaurant and being unable to convince the restaurant owner, because the owner's nephew said that the cookie banner must be there.