The RSA was Result of Foreign Legislation.

The macro State known as South Africa [ composed out of two British Colonies & two former Boer Republics ] did not exist prior to the 20th cent as it was created by an act of British legislation which was passed in the British Parliament.

Quote: [ The South Africa Act passed by the British Parliament in 1909 merged the self-governing British colonies of the Cape, Natal, Orange River and the Transvaal into the Union of South Africa, a dominion within the British Commonwealth. The Act, which served as the Union's constitution until 1961, established a parliamentary regime along the lines of the Westminster model, composed of a directly elected House of Assembly and an indirectly elected Senate. ] The Republic of South Africa Electoral System.

This foreign legislation effectively created an artificial macro State in Southern Africa which joined the conquered Boer Republics with the British ruled Cape & Natal Colonies which had earlier annexed Xhosaland & Zululand in the 19th cent. & wherein most of the non-Boer descended Afrikaner population was living in the Western Cape region. Therefore what this foreign imposed legislation did was to cobble together an artificial mega State structure which lumped the various diverse peoples under a single administration for the first time ever. In other words the creation of this state reversed the natural independent status of various peoples & it imposed a blocking mechanism against the self determination which was expressed by many of its peoples prior. The natural tendency of its peoples [ & peoples in general ] is to gravitate towards independence & self determination which was stunted & reversed when the British imposed an artificial macro State based on an imperial model & then recruited members of the local White population to administer it with their government as a surrogate Colonial ruler on behalf of the British power.

This act was the direct result of the friction which later followed [ the State rulers prevented both Boer self determination / Boer Republics restoration & Bantu political petitions for control of macro State ] as the newly empowered White regimes were reluctant to give up control of the macro State [ with later modifications as per the Bantu homeland independence policies ] they were recruited to administer as their general White constituent population were often concerned about inherently becoming an oppressed demographic minority within a universal suffrage based macro State. The British power elite appeared to have used this unfolding political machination to great success as it later gave them the opportunity to reclaim South Africa under the covert guise of the post Apartheid regimes who are financed & propped up by them. After all the British went to great lengths to set up & impose the macro State of South Africa - even to the point of killing off 50 % of the Boer child population in concentration camps during the British war to conquer the Boer Republics.

Therefore it stands to reason that the British would not just simply walk away from the region [ as the Republic of South Africa has only ever existed in name alone ] nor cede true executive control over to any local peoples of the region. This was confirmed with the basic premise of the South African Act of 1909 being incorporated & thus perpetuated into the various Constitutions of South Africa thereby perpetuating the very state apparatus executive control mechanism [ which perpetuated Apartheid in the past & the neo Apartheid of the present ] which works against the various peoples' desire for ethnic group or nation based self determination. Thus the various Constitutions have retained the centralization of power.