> Systemd does not solve the deployment problem, and will not unless it adds something like a systemd package manager.

It really doesn't need to provide a package manager. Systemd already basically has all the knobs for launching services in their own little world (`RootImage=`, `RootDirectory=` and recently `RootMStack=` (for a de-OCI'd layered container images)) or systemd-portabled. There are probably more things I forgot.