I dont seem to understand why we need to run a Laravel app with
php artisan serve
The `Serve command is just a shortcut for the PHP Builtin Webserver, something PHP has out of the box, so the point of using it is to start testing your application as fast as you could, you just need to install PHP, Composer and your application is up (if you don't need anything else, of course). But if you already have Nginx installed, there is no point at all, just use it.
It's not wise to use the Builtin Webserver in production.