All containers give you a guaranteed build process and proof that mutable state is only stored in well-known locations. That’s a huge advantage over full servers right there as any experienced Unix admin will tell you.

If you’re using a container based on an OS, you are installing far, far less and having only one process running. That again is a huge savings: no time securing postfix and cron, etc.

Another big advantage is that you’re shifting this work from the deployment time to build time. You do it once and can test it as long as you want before deploying it to production - no more failures because Red Hat’s mirror is unavailable or malfunctioning during your prod update window.