The steam wrapper is an optional step the developer can apply (and it does not come by default, and is even a little bit of a pain to setup). Many steam games d

The steam wrapper is an optional step the developer can apply (and it does not come by default, and is even a little bit of a pain to setup). Many steam games do not do this, so they can be launched without steam open. So it's essentially left up to the developer just as an extra protection measure.