Yes Primarily because of the Livestock/Discus for higher o2 exchange, and many of the foods Discus eat are laden with fats, and proteins that choke the waters surface. Other than that I've become a firm believer in skimmers over the years, and I especially like the mechanical efficiency of utilizing natural phenomenon to achieve those ends. Discus thrive on High o2 yet their own preferred temperature, water chemistry, and feed continually put them at odds in a closed system. In nature they enjoy a luxury of dilution a hobbiest could never provide.
Over the years the trends come and go, but somehow people seem to glean individual details whilst the rest zip right by them. Co2 injection IS a boon for live planted aquaria, but Plants DO require o2 as well. Once you throw livestock into the mix what was once a simple balance of chemistry becomes a great deal more complex. Often at the fishes expense, and ultimately our own $$$