WordPress load all required theme dependencies using RecursiveDirectoryIterator from inc

wp-load-all-required-dependencies.php

<?php
/**
 * Required Dependencies
 */
// Construct the iterator.
$rdi = new RecursiveDirectoryIterator( get_template_directory() . '/inc' );

// Loop through PHP files.
foreach ( new RecursiveIteratorIterator( $rdi ) as $file ) {
	if ( $file->getExtension() === 'php' ) {
		require $file;
	}
}