Option 2 isn't stupid, because once you take that money you are beholden to a contract, which comes with both explicit and implicit clauses.
For example Apple would never implement ad blocking by default in Google's Search, not as long as they keep getting payed with _billions of dollars_.
And would Apple even bother to keep improving Safari if they weren't earning so much money from it? Given what happened to IExplorer back in the day, when Microsoft dropped the ball on its development after version 5, I'm not so sure.
Also Safari's content blockers are really easy to circumvent by anti-ad-blocking tech. Doesn't hold a candle to uBlock Origin, which isn't possible to implement on top of Safari. And the available content blockers are so bad many people don't even bother. Fact is Safari is a favorite for ads companies and publishers.
Yes, all browsers are funded by ads, that was the point.