The future of Docker containers is a slow death now that there are better container solutions that provide more benefits and less bloat. Docker had great engineers and developers, but terrible management.
For the majority of people and companies containers == docker. Mostly wrapped by something k8s or one of the cloud container or running locally on your pc/laptop .
Yeah some people are using rkt some are using lxc but that’s the absolute fringe minority (no disrespect intended)