Downtown Cairo has undergone a steady decline in recent years, with more slums developing and more beggars filling the streets. This article from Bloomberg says there are many reasons for the decline.
"These days, unemployed youths shout vulgar catcalls at women shoppers walking past crumbling facades. Vendors on pot- holed sidewalks peddle Chinese-made T-shirts. Legless beggars grab the ankles of passers-by for alms."
"There are graver ills in Egypt's megalopolis of 18 million people: Outlying neighborhoods thirst for drinking water, ramshackle houses collapse on shallow foundations and trash clutters miles of dirt alleyways. Still, the district Cairenes know simply as downtown provokes a kind of longing for possibilities lost in a once cutting-edge and even glamorous city."
"It's hard to pinpoint any one reason for the decline. Rent controls have made it unprofitable to renovate the buildings' flowery stone fronts and Art Deco design. Cairo's penchant for informal housing hurts: Squatters have taken root on rent-free rooftops. Lack of zoning rules has also contributed: Kiosks, whose owners pay as little as $50 a month to do business, fill once-spacious arcades."