More and more themes use Google Fonts, so they don’t have to store fonts locally that, theoretically, will load faster from Google and, incidentally, that all web users can view them even if they do not have them installed on their computer.
But you can get the opposite effect because, sometimes, speed analyzers can show errors precisely with Google Fonts, either because there are delays when loading remotely, or even sometimes because they have changed paths to the fonts, which also happens.
An alternative that you can take advantage of is to host the Google Fonts you need on your own server, thus eliminating remote uploads and the possibility of errors of path changes in the fonts as I said.
To do this you can use a utility called Google Webfonts Helper, which allows you to choose the font you want to download and specify the styles to apply.

Then you just need to do the following:
- Copy the CSS provided by the utility into the stylesheet of your active theme.
- Download the font and unzip the zip.
- Place the downloaded files in the
fonts
folder on your server (create it if it does not exist).

Now you just need to remove the external call to the Google Fonts in the header of your active theme and you will have reduced the external calls to CSS.
Note: Another option would be to host the fonts on your CDN, but for the small size of the fonts you are usually penalized more for making calls to external resources and CSS in speed analysis.