If an advertiser is willing to pay you $x then you can be guaranteed they're earning $x * 2 -- or more. If you had the product instead, and were the advertiser, you could be the one making a lot more money.

Advertising expenditure is always a sliver of total expected revenue, except in two rare cases: when a company bets the farm on an ad campaign, and when the advertiser is a startup running on VC.

Therefore, the amount of money the ad generates will almost always be more than it costs. That is indisputable.

Ergo, making products is a better way to capture more money.