No, that isn't true. Compose can absolutely be used with Docker replacements, and there is no reason you couldn't create an implementation for LXC, for example.
> Compose can absolutely be used with Docker replacements
Can you point to some examples of this?
LXC has profiles which can be mixed and matched for containers, it's got far more extensibility, compose files are a one-shot creation that gets copy/pasted/modified all over the place (we're all guilty of this), you need to read every single compose file and reboot unlike additively popping another profile on a linux container while it's running.
I'd really disagree that compose files are somehow one-shot, or blindly modified. To the contrary, really, we have them checked in with the source code. Upon deployment to the cluster, the (running) services will be intelligently updated or replaced (in a rolling manner, causing zero downtime). LXC might be more elegant, but I have no idea what simple, file-based format I could use to let engineers describe the environment their app should run in without compose.
I need something that even junior devs can start up with a single command, that can be placed in the VCS along with the code, and that will not require deep Linux knowledge to get running. Open for suggestions here, really.