Apple's App Tracking Transparency (if that's what you're referring to, as opposed to Intelligent Tracking Prevention) doesn't even default to anything. It asks

Apple's App Tracking Transparency (if that's what you're referring to, as opposed to Intelligent Tracking Prevention) doesn't even default to anything. It asks you and gives you two equally-prominent options, but indeed even in that case the acceptance rate is still just 4% which I assume is either misclicks or ad-tech people.