Google as an organisation is primarily setup for bucketing users into groups for ads. It's a core assumption thats part of everything they do. Therefor, it's

Google as an organisation is primarily setup for bucketing users into groups for ads. It's a core assumption thats part of everything they do. Therefor, it's not about how much money they make from you but rather that it's really hard for them organisationally to separate users who want to pay to opt out from the rest who are their product. The cost there isn't what they make from you in ads, even if you're willing to pay double - it's the effort for them to switch their engineering to making money off two types of users - those pay not to be tracked and those who don't care.