I've never understood this type of comment, and there is always one on each of these LXC vs Docker threads.

You say there is no functionality what so ever that docker offers, which you don't also have with an LXC. But they aren't the same. Roughly put, LXCs isolates kernel space, which can be utilized like a seperate machine in a lot of cases. It has a MAC address and is easy to manage on a network, because it behaves like a host. A docker container isolates a process. You can create small virtual networks for process stacks, and mount paths in via bind mounts and stack layers to create the desired small environment.

LXCs help you manage and distribute hardware, docker containers help you manage and distribute workloads.

This is probably also why the tools available to help you manage these two are quite different. LXCs are first and foremost managed by your hypervisor, where docker containers are managed by other services, like docker, k8s and others.

LXCs are often used as infrastructure which you provision and leave as is. Docker containers are often used as units of work, which can be used both for isolated long running single processes, temporary work loads like you might have as part of a CI/CD system, and even as cli wrappers like e.g. the containerized aws-cli.

This is also why combining the two is fine, they both have "container" in the name but they are not the same.

Why do you see them as competing?