Admitting they're just an ad company would collapse the delusion that drives their share price.
Google has to be a power for good open source & web. Otherwise they risk losing their whole business to apps & closed Oses, where they have next to no competitive advantage.
Edit: not to forget Google uses their hold on the browser market share to push many platform APIs that only further their own goals with little care for privacy.
edit: removed my quote of the attack since OP did.
Any Google service that doesn’t meaningfully impact the next quarterly earnings should start getting ready for the chopping block.