GDPR puts the citizen/customer in power of their own data. They can ask for their data, they can ask for it to be deleted, they have (however shitty the UX) control over where it goes. They can contact large corporations and request these things and be heard out.
I don't know how to explain it any other way: These things are fucking important.
As for your organization's GDPR expert who doesn't know anything about anything, this sounds like a "your organization" problem. Replace GDPR with some other acronym such as HIPAA, PCI or even SEO or PHP, it's still your organization's fault for hiring someone who doesn't know their stuff. How is that GDPR's fault?
Edit: Yes, keep downvoting facts. GDPR isn't just cookie warnings, how is that controversial?