Google wrote the "PageSpeed Insights will use data from the Chrome User Experience Report to make better recommendations for developers and the optimization score has been tuned to be more aligned with the real-world data.
In fact, Google shows two metrics, First Contentful Paint (FCP) and DOM Content Loaded (DCL). Google will rate your page Fast, Average, or Slow based on both metrics. So if both metrics are in the top one-third of their category, the page is considered fast.
Page speed is a critical factor when it comes to ranking your website higher on Google’s search engine results.
If your website isn’t on par with the top 10 organic pages, you won’t rank on the first page. And the vast majority of search engine users simply won’t click to the second page. It’s no secret that the top 10 results will generate the majority of clicks.
So focusing on page speed is paramount to having a successful company and a website that converts.