If you switch to FreeBSD then you'll have.. jails.. which are like entirely the same thing as containers.
Anyway it's the "Ubuntu Core" edition that's new, not containers, and it sure would be entirely optional. It seems to me it's a set of tools to spawn many copy-paste server instances in a gigantic "cloud" farm depending on level of activity or need to scale up. That's trendy but totally useless if you have the more usual need of caring about "that one server".
But a container is maybe like running a process as a chrooted user and not much more if you want to keep it at that. I will liken it to running Apache as non-root and using its virtual hosts features, perhaps that's similar work and benefits. So you might find some simple and boring tool if you ignore the hype and the various competing management layers. I seem to understand you can manage processes with cgroups to get the I/O, CPU, memory limits whether or not you use containers, too.