Why would Firefox block Google’s ads on Google’s own site? That’s not what Firefox’s tracking protection is about. Firefox protects people from third-party tracking, it’s not an ad blocker.
If a website wants to show its own ads -- let’s call them first-party ads -- then Firefox is completely fine with that; and so it every other browser, including Brave.
https://bugzilla.mozilla.org/show_bug.cgi?id=1582752#c1
If Firefox blocks Google search ads, then Firefox is dead ;) It's that simple.