Some WordPress themes and plugins have Google Maps API built-in and unfortunately sometimes don’t have a way to turn it off. Google maps, unfortunately, can wreak havoc on your site’s performance, even though the requests are loaded async. Typically a request is made via the official Google Maps API to the following URL:
//maps.googleapis.com/maps/api/*
There might also be additional requests to the following URL:
//maps.gstatic.com/mapfiles/*
And here is an example of a map plugin running on WordPress. Take a look at all the requests made to Google Maps. 20 HTTP requests just to load one map. Depending on the integration there might be fewer or more requests.

Disable Google Maps API
Follow the steps below to disable Google Maps API. Note: This will, of course, break your maps, so only use if you aren’t needing Google maps on your site.
Step 1
Click into the Perfmatters plugin settings.

Step 2
Under the “Options” tab and “General” sub-navigation menu, toggle on “Disable Google Maps.”

Step 3
Scroll down and click “Save Changes.”