You don't have to use Docker for everything. I personally use Docker for services my application needs (Docker, Redis, etc) and Nix for the application itself.
I do something similar (minus the Nix part). I don't bother to dockerize my applications, but I use Docker as a cross-platform dependency manager for daemons they use. Before that, I used Vagrant with a full VM, which has the benefit of looking more like a provisioning script for a full server, but the down-side of being tied to whatever OS or distro you choose for the VM.
Either way, it's a way to document exactly how to get your dependencies in order and the project running. That's a big improvement, operationally, at a lot of places. If Docker died tomorrow with no replacement, I'd go back to the Vagrant thing. Installing that stuff directly on my workstation sucks, for a bunch of reasons, and I'll not go back to that if I have any way to avoid it.
Either way, it's a way to document exactly how to get your dependencies in order and the project running. That's a big improvement, operationally, at a lot of places. If Docker died tomorrow with no replacement, I'd go back to the Vagrant thing. Installing that stuff directly on my workstation sucks, for a bunch of reasons, and I'll not go back to that if I have any way to avoid it.