One purposeful use for quantum computers is running simulations, as it can be expected that results from a quantum simulation (read: real quantum computer running a controlled simulation of a particular process) will work identically when applied to that process everywhere else.
For example, there is great hope that we'll eventually have quantum simulators that predict chemical and drug reactions and performance without needing to use the actual drug or chemical on an actual guinea pig. These simulations are on real quantum computers, using real quantum behaviours.
This works barring the discovery of another competing set of quantum rules, but nobody is currently expecting that to happen.
Also the article describes the very real quantum computer these simulations run on.
TL;DR: A quantum simulation is not the same thing as a quantum computer emulator. You'll hear a lot about quantum simulations, but they are nearly always in regards to real quantum computing.