How so? The law doesn't require cookie banners. However, you could argue that tracking/advertisement cookies should have been banned completely and that the law is flawed in that it allows for tracking given user "consent".

It was not a flawed idea, but flawed execution. The law should have mandated to adhere to the user's "do not track" setting in the browser.

That being said, it was very early regulation in this field, and more recent approaches are already better, e.g., GDPR, DMA.