Page Speed and Page Rank
https://techspective.net/2019/10/14/the-effect-of-page-speed-on-google-ranking-and-seo/
In 2018, Google announced that it was using the speed at which a webpage loads as a factor in Page Rank. A website with lots of media, such as photos and videos, will typically take longer to load than one with only text; however, it is possible to program media-heavy pages so that they are not noticeably slower than a page with less media. Slower pages often gives users a bad experience because users do not want to wait too long for a page to load, so by prioritizing faster pages, Google is prioritizing the pages that will give users the best experience.
Web designers have always had to consider speed in making their sites because users will be less inclined to visit a website if it is too slow. However, with speed now affecting Page Rank as well, programmers have an extra reason to make sure their sites load as quickly as possible. While Google does not say exactly what the parameters for counting a website as “slow” are, they likely do not differentiate between pages that are on the fast end of the spectrum. While one site may technically be slightly faster than another, if the difference is unnoticeable to the user, there is no reason for Google to penalize either site. Page Rank is also based on many factors, and speed is far from the only determiner of a site’s ranking. However, by providing incentive for pages to be fast, Google is encouraging good practice in web programming and trying to ensure a good experience for the user.