Most of the electronics I've had over the years has been very durable. But the one weak spot can be cables/connectors between equipment. For example, I've had the charger plug for laptop break multiple times, necessitating replacement of the charger. Only one time did the connector in the laptop itself go bad, but it can happen. Or, think of your cell phone charger cable -- I've also had several of those go bad over the years, but cell phones tend to be plugged in daily.
The DAC not only has the power connection, but also has signal in/audio out connections, so that gives you a couple of other points where you want to be careful. Finally, for many audiophiles, they upgrade things like DACs on a regular basis. You may have moved on to new gear before you've had a chance to wear anything out.