I don't have a sign in front of my house saying "Beware of the dog", because I don't have a dog.
(1) Identify the issue; (2) Quote all relevant rules; (3) Analyze the rules in light of your specific factual circumstances; and (4) Reach a reasonable conclusion based on your analysis of the rules.
This is how your company's legal team is making recommendations to management. You have to fight fire with fire. The only advantage your legal department may have over you is access to more comprehensive legal research services like Westlaw and LexisNexis. But at the end of the day, all they're doing is researching what the law is and how the courts are interpreting the law. Search for the right terms on Google, and you can do a pretty damn good job at crafting credible arguments. We don't need the lawyers always acting like they're at the top of the food chain.
(See also https://knowyourmeme.com/memes/a-lot-of-questions-already-an... .)
You might instead consider asking people why they're asking, and figuring out ways to promote more widespread understanding.
Concretely: you might actively promote adblockers and tell people why they should use them. And rather than saying "we don't use tracking cookies", you could explain "here's why so many sites have cookie banners, here's why we don't".
(weak argument but somewhat funny).
Lawyers are ultra cautious. If you can -guarantee- that no one is going to magically add tracking/google analytics or some such to your site than sure, tell them you don't need the banner.
Also: it might be interesting to try and find some metrics on conversion impact for those stakeholders. You're making the product worse.
And at some point in pushing back, disagree-and-commit is the right thing to do.