The goal of AMP is to provide a better user experience by delivering content as instantaneously as possible. Google’s ranking algorithms have been focused on page load times for quite awhile.
Data collected by Google and SOASTA found that 40% of users click off a page if it takes longer than three seconds to fully load.
You have only three seconds to keep the attention of a user who with one click can be on your competitors website. And if your web page fails to load in those three seconds, you created that content in vain.