I think the real benefits of Docker don’t become unquestionably obvious untill you’ve ever tried to manage more than one installation of some kind of server software in the same machine and inevitably learn the hard way that this comes with a lot of problems and downsides.

• From simple things like if the environment needs a restart, you can just restart the container, without rebooting the machine, interrupting other applications.
• To seriously dangerous and problematic things, like configuring your system to work with your new application only to realize that this configuration is breaking your other server software.