Search Engine use page loading speed as a ranking factor. The Search Engine spiders can estimate your site speed fairly accurately based on a page’s code and filesize
Page code and file size affect the speed of the loading page. A page that takes more time to load is not preferred by Google.
Google at times uses Chrome user data to handle the page loading time better as it takes into consideration the speed of the account server, CND usage and other signals that are not related to HTML.