The camera pop-up flashes and the “lower end“ flashes can only illuminate in front. Most “good” flashes allow you to bounce the light instead of just sending it straight in front. You can bounce the light to the ceiling or even behind you toward a corner or a large reflector.
Regular hot shoe flashes have only one power setting: the full power. To throw less light, they cannot reduce the power, they reduce the time of the flash. A ½ power is just the same amount of energy but over ½ of the time. A ¼ power is just the same amount of energy but over ¼ of the time... just like a camera shutter.
Camera manufacturers have spent millions upon millions to simplify the flash and make it work with bounce, slave, remote... Take advantage of it.
My standard settings for the flash operations for the camera (I even have it stored as C1) are: