SQ have cut back on their regional infliight service quite a bit over recent years and your example shows more that the direction of travel on short flights is towards less service in return for lower costs. It's just that with compdtition from LCCs, Europe is much further ahead in that that game.

BA have moved to two (typically Airbus 321) Cairo flights a day, which is quite an incease in capacity over the 787 that most recently served the route as longhaul, which suggests more prefer the opportunty of cheaper prices. CAi-LHR flights can be below 100 pounds one way, somethung that I can't recall seeing when it was a longhaul operation.