Yes, containers are more than chroot, until you:
- Want to give them their own IP addresses or networks, or
- Put upper bounds on their resources, or
- Get tired of dealing with chroot and unshare and seccomp and probably other tools I'm forgetting, or
- You want to run an arm64 container on an x86 host with minimal configuration, or...
this is a really fun (and important) exercise for anyone working with containers seriously to undergo but let's not trivialize how insanely easy Docked made creating containers become.
Bocker[1] does a reasonably good job of showing the value of Docker was mostly in Docker hub.