I can assure you there's companies that spend a millions on ads with no idea what they are doing. In-fact there are products within business units, within large enterprises that spend >$1M per quarter, where the segment itself may spend $5M+/Quarter, easily.

The agency that runs the programs the the only people that win - after they pocket their 5+% commission.

Source: past roles where I saw a lot of people who do not know wtf they are doing with ads (yet they themselves are making 6 figures)