What are the potential consequences of using external servers, like Layer-Ads.de, for serving content in PHP websites?

Using external servers like Layer-Ads.de for serving content in PHP websites can lead to slower loading times, potential security risks, and reliance on a third-party service that may be unreliable. To mitigate these risks, it is recommended to host and serve content locally whenever possible.

// Example of serving content locally instead of using external servers like Layer-Ads.de
$content = file_get_contents('local_file.html');
echo $content;