At its core, SEO is about generating leads and revenue by helping your website perform better in organic Google Search.
Google’s goal is simple, to make money. The search engine does this by providing great search results over and over again. This in turn keeps its users consistently coming back to search for more intent targeted information.
Ultimately, they are hoping for visitors to click their Ads, a big profit center for Google.
By helping your website provide a positive user experience (great/trustworthy content), along with making sure your website is friendly for Google from a technical perspective (finding/processing content), then Google will want to send users to your website over your competitors.