Think about how often that box needs patching for code outside of your app and you’re talking load-balancing, autoscaling, etc. to avoid downtime or overloads, but also paying for idle capacity. Then, of course, you have to think about security partitions if anything you run on that box shouldn’t have access to everything else. None of that is unknown, we have decades of experience and tooling dealing with it, etc. but it’s a job that you can just choose not to have and people often do, especially for things which are bursty. There’s something really nice about not needing to patch anything for years because all you’re using is the Python stdlib and scaling from zero to many, many thousands with no added effort.

Scale down to actual 0, really easy edge distribution, stupidly simple to deploy to. That's really it.