That's also why most insurers prefer to write the car off if the damage is anywhere close to 50% of the cars valueThis is true.
But........
The prices of parts to repair the car, the labour costs and the price of materials such as paint increase due to Rand values and inflation so the costs for a repair job has to be factored into the price of the premium. Since there are far more claims for repairs than write offs, the value is off lesser risk.