Of course, you can do that. It’s the strategy Etsy used, for example. Point still standing, that makes deployments definitely more complex than just „uploading a file“.
And then again, you’ll end up wondering why your servers should waste cycles upon cycles for executing the same bootstrap code over and over again, if they could instead only do that once, keep the app in memory, and only execute the request handling code… and just like that, you’ll end up with Octane, or Swoole, or what-have-you.