We run all our sites to the recommendations that are given by Google in the developers tools for user experience improvement.
So - putting it simply - Google Analytics measures how long it takes to load every script and file on the page; everything. But this doesn't tell the whole story (a lot of those files are invisible to a user and don't affect user experience).
Google developer tools recommendations include 'lazy loading' or 'smart loading' (especially for mobile) to improve UX. This is when you front load the most important files - getting all the main content up in front of the user immediately, and taking more time over non essential files (like the ads or the fb button etc).
For example' non-blocking java script loads later and this is deliberate. Which is good for mobile user experience (speeds up the page on a mobile handset with limited processing ability) but 'bad' for the page load speed metrics as reported in Google Analytics.
So if you're looking at the Google Analytics page load speeds, then remember that they don't tell the whole story. Ezoic is built to do everything to improve User Experience. Which is why our Google PageLoad Speed scores (esp mobile) are so much better than most sites because they benefit your users' experience of the site.