I believe that part of why Google is so invested in Chrome is this very thing. They don't want users to have more control over cookies and tracking via the browser.
One of the first things people would do if they really had control over their browsers is start blocking Google Ads. Google realized this early on, it's a huge potential threat to their main source of revenue, so they launched Chrome to influence, and eventually dominate, the browser market.
Google doesn't want users to have more control when it threatens their bottom line. It's part of why they've been trying to block ad-blockers.