Google rankings mainly depend on the website's trust and authority signals. Spam score is an indicator that tells how risky or genuine your site appears to search engines. If the score is high then ranking may drop and there may also be a penalty risk for the website. By maintaining a low spam score you can make your site safe and reliable for search engines.
Also read: https://www.batterseawebexpert.com/blog/what-is-spam-score-how-to-reduce-it/