To fetch the post count based on all user roles in WordPress

$roles = get_editable_roles(); // Retrieve all user roles

foreach ($roles as $role_key => $role_details) {
    $args = array(
        'role'    => $role_key,
        'orderby' => 'login',
        'order'   => 'ASC',
    );
    $user_query = new WP_User_Query($args);

    if (!empty($user_query->get_results())) {
        echo '<h2>' . $role_details['name'] . '</h2>';

        foreach ($user_query->get_results() as $user) {
            $username = $user->user_login;
            $post_count = count_user_posts($user->ID);

            echo 'Username: ' . $username . ', Post Count: ' . $post_count . '<br>';
        }
    } else {
        echo '<h2>' . $role_details['name'] . '</h2>';
        echo 'No users found.';
    }
}

get_editable_roles() function to retrieve an array of all user roles and their details. We then iterate through each role and perform a user query for that specific role. Inside the loop, we display the role name as a heading.