Probably more like selection bias. Sites that are heavily monetized with Google have relationships with them and can work directly with them to improve their SE

Probably more like selection bias. Sites that are heavily monetized with Google have relationships with them and can work directly with them to improve their SEO and page rankings. Plus if they have all those ads they almost certainly also use Analytics, which can help them optimize too. But also, if someone claimed to be a Google engineer and told me they purposely rank up pages that have Adsense on them, I wouldn't call them a liar immediately.