A PHP file has less dependencies than a Go binary. There's over half a billion websites. There are probably under 20 million people in the world who know what a "static binary" is, fewer still who have the knowledge and resources to deploy one on the web. The vast majority of people with websites can use this PHP file as-is, with no additional learning or work -- just FTP it over to any penny host in the world. They'd not be able to do anything useful with a binary file.