Nothing defines a fictional world more readily than its technology. When you see a well crafted machine design, you instantly understand the setting and civilization shaping it. Tech builds worlds, but only when grounded in reality and familiar things. A futuristic gun feels real when the audience can feel the weight of it in their hand. They need to feel the wind in their hair when piloting that speeder. They need to hear the inquisitive beeps and boops of that robot crawling around.