There’s no doubt that Google’s PageSpeed Insights is one of the most internationally used page speed measurement tools, and for good reasons. The Google team has always been on the front line of web performance optimization tools. Over the last ten years, they have developed a series of performance tools dedicated to different types of users: from developers to marketers to amateur website owners, there’s a Google tool suitable for every need!
Higher PageSpeed score doesn’t guarantee that your site will obtain higher Google’s rankings so speed score alone is not an indicator of an “SEO grade.” As there’s not a direct connection between how your site scores, and the position it will gain in the search results pages.
But, since the PageSpeed score is the result of overall performance analysis on a few specific metrics defined by Google itself, the better your score, the more you can assume your site is in good shape and overall in good healthy condition. A good score is a fair indicator of the well-being of your site in the eyes of Google.
Given that Google’s scoring system rewards websites that achieves satisfactory PageSpeed performance results, it is always recommended focusing on increasing speed scores and please Google for the same. A faster website has higher chances of being loved by Google. Your efforts should be focused on making sure your website loads as fast as it can.
To conclude, it is most likely of your website to get rewards by Google if you have better PageSpeed scores but it won’t be sufficient just on the score parameter. The real indicator of quality is still its load time and how well you are visible to Google from content prospective.