AC power was the electricity that Tesla worked on. AC power was easier to transmit, as using a transformer, its voltage could be increased past what DC was currently capable of. This allowed for less power loss during transmission. Also, AC electricity was easier to generate compared to DC. Furthermore, the AC induction motor, invented and patented by Tesla in the 1880s, was much simpler compared to DC motors, which required components such as brushes and commutators. This reduced the maintenance, which led to factories using AC electricity.
Most modern day technologies utilize AC power. The increasingly popular fluorescent light bulbs run on AC power and would be difficult to run using DC power.