I first heard about containers in 2012. I went to a conference on software delivery and talked with a gentleman that was using them in his Java application, mostly because the Java app had version issues and would leak memory. He could run hundreds of instances of the app on each server and handle a load, allowing each to be built, run, and then get destroyed in minutes.
Since then, I've come to appreciate containers as a way to isolate workloads of specific applications. They became very popular a few years ago, and many developers and companies were looking at them. Since then, the hype has cooled, but I find that the used of containers is still growing, and certainly my use is growing as well.
In the last year, I've experimented with a few different pieces of software in containers. Rather than try to install a number of dependencies on my system, I've downloaded a container, mapped a volume, and been up and running much quicker than I would have been otherwise. My experiments with Jekyll were one of the recent examples.
I also got a demo from someone at Redgate recently that included a container file, allowing me to use VS Code, but develop and run in a container, avoiding dependencies on my machine. I was up and running with this software in minutes. I was truly impressed with the ease of getting started, and the simplicity for me to actually run and debug code.
I still don't see a lot of database container work in production, or even in development. We get requests from customers, but often it's a wish, and they aren't even sure how they'd get started. While I think database development with containers is fantastic, you do need to have a good dataset available that you can use inside the container to keep resource usage low and make this a viable environment.
I still expect the future of database development to be in containers, especially as we start to have more and more applications connecting to multiple data sources. That's going to take some time, but I still think learning about, and experimenting with, containers is a great skill for you to have. It's also an impressive topic on which to have a few stories ready for your next interview.