This isn't about having an adversary now, this is about minimizing future risk. A database of personal data is one index or scan away from being used to Target someone. Imagine what the Soviet government could do with information about your purchasing habits, organization membership, political leanings, religious participation. It's happening right now in China.
The fact that you don't have anything nefarious to hide doesn't mean you shouldn't be worried about the existence of such databases. I'm not hiding drug and weapons deals from the NSA, I'm trying to minimize how much information about myself leaks to people who have no business collecting it. All people should be similarly cautious. Unfortunately this isn't the kind of thing that matters to most until it's too late.
How many laws or executive orders or judge rulings do you think it would take before even the U.S. government could trivially abuse such information to target someone? What if you're a whistleblower like Assange? What if you piss off the wrong police officer? You haven't heard of corrupt cops harassing citizens and who stuck their neck out a little too far?
Bad actors exist all over society. It is only rational to minimize the amount of ammunition they may have against you, even if you aren't planning anything nefarious. The problem with this kind of digital surveillance, regardless of whether it is by government or corporation, is that the stored data is permanent and easily harnessed. Let's not even get into the power that such bits and pieces confer to actors with access to even simple ML technology.
I don't understand the reaction that people seem to have toward the desire for maximizing privacy.