Yes, containers and unikernels are possible answers to the same issue. If you consider an application running on a virtualised OS you have three layers: hypervisor, os, application with some duplication of functionality between the hypervisor and the os.

From there, if you want to simplify you can either add hypervisor-like isolation functionalities to the OS (containers) or move the little that’s actually needed from the OS into the application (unikernels).

That’s why Docker bought MirageOS a few years ago.