Direction of the light is most important.
What you use to control direction is based on the situation and its fluidity.
Umbrellas are nice and useful modifiers when you have time and control of a situation.
bounce, off a wall or wall/ceiling joint are available with some discrete planning and aiming of an on-camera flash in a fluid situation.
Which is better. That depends on the situation and the creativity of the photographer.
For example, I could have spend 5 minutes or more setting up an umbrella getting my subject into position and making several exposures to make sure I had it right. Or, I could bounce the flash into a wall/ceiling joint, used ETTL for exposure and have this result;
BTW, the bounced flash was for fill. The main light was from a sliding glass door to her balcony.
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