I tried to use it, but it didn't remember the "no" answer. Every time I loaded a page, the same confirmation for the same cookie was presented again and again.

Yeah, but that's still way too narrow to capture what the law is about. The GDPR doesn't really care about cookies, or storing data on clients in some way. Instead, it's about end-users giving informed consent to processing their data. Not just by hand-waving away some disclaimer, but actually conscious of the consequences of that action, and why it is necessary to do so.

I know this sounds all lofty and Brussels ivory-tower-ish, but I'm absolutely convinced it's the only sensible way to deal with personal information - even if American companies insist on forcing a new normal of lacking privacy on all of us.