> Companies are under no legal obligation to make those banners as obnoxious as they are

Actually every single lawyer we asked about implementing GDPR advised us to have one of those obnoxious banners. Because the law is so ambiguous and the penalties so high that is better to play it safe. And we have no ads nor tracking at all on our product website.

You can ignore your lawyer's advice if you want, but it's a bit like a lawyer office ignoring my data security and backup advice: assuming a huge amount of risk.