We certainly have plenty of problems.
IMHO, one of the key flaws was the acceptance of corruption & croneyism from the very start of the New South Africa, from the very top.
The inequalities are in our faces in ways that most developed folk can't comprehend.
The problem is indeed beyond just the constitution, or even the culture within a single country. The world is a complex, interconnected dynamical system, and all equlibria will be unstable, I suspect.