This only does code. You'd probably have to do those locally and SCP them over or, yeah, some mount magic.
> What happen when you need to work from a shitty internet network ? In train ?
You'd have to commit your work, but you'd be able to bring the environment up on your laptop. There are still merits to this, such as the repeatable nature of containers. Depending on where you've worked, you may have been through the hell of a huge list of setup steps when on-boarding a project: that's one thing that containers are really good at automating.
You may not be the target audience, though.
VS Code remotes allows you to drag and drop files from your desktop and they're placed where you want them in your remote environment. I don't understand why this would be any different.