As of April 30, 2020, the current version of Google Cloud Platform’s WordPress Click-to-Deploy deploys WordPress 5.2.3 using PHP version 7.0.33. PHP 7.0.33 was released in January 10, 2019 and since then the PHP developers have released the most recent and stable 7.4.5 version. As a site administrator it is highly essential to update system versions in order to improve both security and performance.
There are many blogs – especially the article from WordPress themselves – which go into details about why updating PHP is important. Since I would be spitting out the exact same details I will not write about it here. However, pages I have visited would simply ask WordPress administrators to contact their webmaster/sysadmins to update the PHP version, which will not fly for an amateur such as myself. In addition, building from source often results in faster performance, so I took on that challenge as well. To serve as future reference, I have created a manual in the process of updating this site from PHP7.0 to PHP7.4.5. Continue on for steps on how to do it yourself!