Well, they also had astrological and religious uses. In fact, the top of the Wiki article states:

Its many uses include locating and predicting the positions of the Sun, Moon, planets, and stars, determining local time given local latitude and vice versa, surveying, and triangulation. ... In the Islamic world, it was also used to calculate the Qibla and to find the times for Salat, prayers.

But sure, a device specialized for a single purpose should normally out-perform a multi-function device used for that same purpose.