I know you can do this with VMs too, with tools like Vagrant, but containers start in a couple of seconds - great for integration tests.
It is amazing how many technologies get traction simply because "It lets us bypass IT."
To manage our IT had to make certain infrastructure decisions and build their competency around those. This clashes with a lot of modern development, but we manage with docker and an increasing Azure presence. It’s not optimal, but sometimes it’s just necessary. Don’t get me wrong, we’re trying to improve and build Devops that isn’t handing off a container, but it’s a challenge in sectors where digitisation and IT aren’t priorities despite being an inherent part of any business process in 2019.
There is a real danger in there of course, but we have strategic choices for our development platforms as well. They just need to move a little faster than IT.
For Linux containers there is LCoW, which uses a Linuxkit VM to host the containers.
There is also some chance that in the future Linux containers will run natively on Windows without a VM, via WSL. This is very hacky at the moment but there have been reports of people being able to run Docker engine in WSL with no VM.
Whether MS ever use that tech. for production linux containers remains to be seen. It sounds kind of cool and might be good enough for dev/test but I imagine sorting out all the wrinkles to make it prod. ready could be tricky...
Ten years ago we build things in C#, used MSSQL and deployed to IIS. All Microsoft tech, all pretty straightforward, except it wasn’t. We never kept track of the “it works in dev, but it explodes in prod and I don’t know why” hours, but I wish we did. Because it’s in the thousands, and those thousands of hours is exactly why we use docker.
We also use docker because it lets us build things that our IT crew isn’t certified in running infrastructure for (and the lovely security issues that brings to the table) but we mainly do it because it works.
Docker might not have a monopoly on that, but they have enough of a brand that the word “docker” is to containers what “google” is to search. At least in my circles.