A couple of naive questions:

Isn't more expensive to run docker upon Linux and deploy your applications instead of installing the applications and it's dependencies directly on the Pi?

How is this going to work on underpowered machines such as the RPi?

Is it for applications that require a very small amount of memory? (say you can run 5 applications that consume 80 MB each?).

Maybe I erroneously tie-up Docker with web-development and web-based applications, but can you give an couple of example applications that could benefit from docker on the Pi?

thanks