It's messy. Dockers superpower: You can write a crazy ass python application that needs dozens of dependencies and weird software configured. You put it into a container, you can update and publish the container with a single script call. Other people can install that, set some variables and not have to install the dozens of other pieces of software. They also don't have to worry about updates.

But that's not to say you don't have to worry about networks, storage and ports.

Then the simplicity of the configuration of containers depends upon the person that made the container. Maybe they wanted to be very flexible and there are dozens of things you need to set. Maybe they didn't include the data store internally in that container and you need your own data store in another container.