Most advertisers care about what ROI they'd get for their particular business. And the easiest way to determine that is with a test campaign of just a few hund

Most advertisers care about what ROI they'd get for their particular business. And the easiest way to determine that is with a test campaign of just a few hundred dollars. Most platforms even give you "free credits" to do exactly that (in many businesses, a few hundred dollars can be a big barrier, because the employee doesn't want to put it on their personal credit card, yet getting the paperwork in place to go through the accounts department is a lot of work). That means the platform-wide stats don't really matter. What matters is how cheaply the platform can get the right ads in front of the right eyeballs who will click through and buy a product. How well the platform can attribute purchases is a big part of it too. Thats why people like youtube have "Which of these companies have you heard of? A. Amazon, B. Gucci, C. Flambaths" surveys - because that's their way to measure (and charge for!) brand adverts which don't lead to direct sales.