There's no reason they can't do both especially considering privacy-conscious people and those adverse to advertising are the very people advertisers would pay a lot of money to reach.
My theory with this is that someone privacy-conscious, ad-adverse and those who block ads signal both that their time is too valuable to be wasted by advertising and they have the skills to install technical countermeasures against them. This correlates favourably with developers and similar positions that typically have higher than average salaries (thus more purchasing power) and the possibility of influencing purchasing decisions at their company for enterprise products.
People who avoid ads aren't even considered a target audience. They exercise too much critical thinking for advertisers who want to grab people by the feels and get them to buy their product for a dopamine rush.
Thanks for the added perspective, you're definitely correct. Measuring penetration is a big deal for price setting ad space. Even still, it doesn't seem to push Google to include their Ad ID system in AOSP instead of the Play Store. They could have forced ROM developers to go digging for the API to remove it.
