PyInstaller is hackish though, I had to add tricks to setup.py by trial-and-error until I found why some config file or sub-module of a sub-package wasn't included when everything else was. It's also slow to launch, because it extracts the code into a temporary directory before importing python.dll, which then imports all the rest.

Containers are fine for a server after installing the runtime, which is already one too many steps. There isn't a self-contained app format that can run without installing something else before starting it.

Containers are not architecture-agnostic. In theory they are not even kernel version agnostic, though Docker seems to work around that.

“Containers” are basically Linux only and that means they can freeride off Linux’s really stable userland api