Hydroponics uses less
energy per unit of food produced, as compared to aquaponics. Hydroponics uses less water per unit of food produced, as well. Capital investment, points of failure, and fragility are all much higher with aquaponics vs hydroponics.
Aquaponics is very energy intensive compared to farming in soil, and even hydroponic systems (there are numerous no electricity hydroponic methods). People with cheap grid connections tend to overlook this issue, but at the end of the day, I have not seen many aquaponics systems that produce more energy than they consume.
In these areas (energy and water efficiency), hydroponics is superior to aquaponics.
There are numerous soil farming methods (wicking beds, swales, etc) than can match Aquaponics in terms of water use per lb of food produced.
Aquaponics is really a compromise between hydroponics and recirculating
aquaculture. Both hydroponics and recirculating aquaculture are typically a lot more efficient in terms of energy consumed per unit of food produced than a typical aquaponics system.