PHP has a way to compile entire applications into single files, for what it's worth. You can compile it all in your CI/CD and then push the PHAR file to all the servers (instead of the thousands of regular files). I don't know if it accomplishes everything you're after, but it's been a PHP feature for over a decade. https://www.php.net/manual/en/intro.phar.php
As the op said: "There are tools for creating stand-alone executables from PHP source code, but they're not as nice to use, compared to languages that were designed for this."