The most accurate (sacrificing probability) answer is "Google's ranking algorithm is proprietary; nobody can independently verify whether they up-rank sites that display Google ads by looking at the source code." Attempts to figure that out from the outside via black-box testing are complicated by the simple ubiquity of Google ads; there's a lot of conflating signal that would have to be tuned out (even if one observes correlation between top search results and Google ads, one has to control for the probability that any random site has Google ads on it, or that ads pay for the SEO and information collection that tends to result in a site that ranks highly in Google results, or even the probability that a site without ads, having found itself high in the rankings because it's delivering data that Google concludes is valuable to users, wouldn't respond to that observation by putting Google ads on their site to capture money otherwise left on the table).
Officially, Google claims it does not [https://ads.google.com/home/resources/seo-vs-ppc].
The most accurate (sacrificing probability) answer is "Google's ranking algorithm is proprietary; nobody can independently verify whether they up-rank sites that display Google ads by looking at the source code." Attempts to figure that out from the outside via black-box testing are complicated by the simple ubiquity of Google ads; there's a lot of conflating signal that would have to be tuned out (even if one observes correlation between top search results and Google ads, one has to control for the probability that any random site has Google ads on it, or that ads pay for the SEO and information collection that tends to result in a site that ranks highly in Google results, or even the probability that a site without ads, having found itself high in the rankings because it's delivering data that Google concludes is valuable to users, wouldn't respond to that observation by putting Google ads on their site to capture money otherwise left on the table).