To be fair the cost of ads varies based on demand; advertisers wouldn't pay more than the ROI they're seeing from their ads, so the prices have the cost of ad fraud somewhat priced in?
Most marketing departments I've met don't check their ROI. They request budget, spend it on campaign, then make power points to tell the rest of the company that they were successful.
Dunno who you’ve worked with but in 2021 that’s patently false. Optimizing Facebook ad performance for ROAS is a precise science. Marketing budgets are heavily scrutinized and hard to defend precisely because of dismissive attitudes like this, so you better believe most marketers are working their tails off to measure and deliver ROI.
