Which, architecturally, is a reasonable objection. But Google runs one of the largest ad networks in the world, so even if a given content creator doesn't run Google's ads, they've probably considered it, and have definitely heard of them. Unless you're deeply involved with online advertising, clicks, impressions, CTR, CPI, cost-per-action, cost-per-click are just noise; content creators want to create content, and be compensated for it.
It's a different market to chase money from people that actually read their content instead of companies who want to sell their products, and outside of a few large paywalled sites like Bloomberg or WSJ, many attempts to charge for content online have failed - but the conundrum is they don't fail for lack of readers, just lack of readers willing to pay.
As far as privacy issues, compared to 2 billion active chrome installs[1], the 611 million people that use ad-blockers[2] is only 30%, assuming they're all using Chrome (which I doubt), and even then, privacy tracking blocklists aren't turned on by default, so the percentage of Internet users that know about the privacy aspect, and care deeply enough about it to do something, is surely smaller still.
Google, then, is one of few parties with enough clout to create such a system and possibly prevail. Content creators have already explored a relationship with Google, many end-users already have logins for Gmail, and many have already paid Google directly in some fashion (Google Play store on Android).
[1] https://techcrunch.com/2016/11/10/google-says-there-are-now-...
[2] https://pagefair.com/blog/2017/adblockreport/