Some apps offer to move themselves to /Applications on first launch. Still, there's the possibility of users clicking "Cancel". Even then, it's a bit more code

Some apps offer to move themselves to /Applications on first launch. Still, there's the possibility of users clicking "Cancel". Even then, it's a bit more code to write, test and pay for (from the POV of a client). Wrapping the bundle inside a .pkg instead of a .dmg solves the problem "for free".