Fewer skilled laborers are needed. And materials are readily available at lower, more stable prices.
Less labor is required, and construction can begin even before the building design is complete. Multiple phases can be worked on simultaneously. Since the floor slab is poured first, electricians and plumbers can begin work sooner.
Solid concrete contains temperature fluctuations better, so less air conditioning is needed.
Solid walls provide greater security against intruders, are more fire resistant and can withstand windstorms and earthquakes, which also saves on insurance premiums.
Aesthetic enhancements such as a variety of colors and textures are achievable at costs comparable to the most basic industrial building.