“The changes that site owners make to improve on these aspects work towards making the web more delightful for users across all web browsers. Investing in these critical user-centric metrics helps to drive usability improvements for users and helps businesses see increased engagement.”
When the update rolls out you will only be able tell if a page is considered fast by long pressing a page link and seeing if it says ‘fast page’ next to a tick icon.
But Google told The Verge that the long-term plan is to start putting fast pages higher in search results as one of the metrics considered when presenting links. This might mean, theoretically, that slow loading pages with good content will get ranked lower as Google considers them a worse user experience.
Labels are now live in the Chrome 85 beta but you can try it out now on older versions by going to chrome://flags in Chrome on Android and enabling “Context menu performance info and remote hint fetching”.