…or to anyone who can walk into a big box store and grab a product off the shelf.

…but you have to get whatever it is you’re transporting to the moon first

No, but you’ll have much more overhead. I have a VM that hosts all Docker deployments which don’t need much disk space (most of them)

This is a big point. One of the key advantages of docker is the layering and the fact that you can build up a pretty sizeable stack of isolated services based on the same set of core OS layers, which means significant disk space savings.

Sure, 200-700MB for a stack of core layers seems small but multiply that by a lot of containers and it adds up.