People want to have a cake and eat it too. Without truth and reconcilation. They want the truth of what happened and punishment of those who did it. Achieving both would probably have been unrealistic. Few if anyone would have spoken out openly about the crimes they did if they would have been punished for those crimes afterwards.

If those in power who committed the attrocities had known they would all get persecuted, then there is no way they would have given up power. One would have ended up with a bitter and bloody civil war.

It is also worth noting that crimes was comitted on both sides ANC had a terrorist wing which bombed places and killed civilians. Truth and reconcilation also meant the people who comitted terror did not get punished either.

I am not taking sides on what approach would have been best. That seems like a complex question. I just pointing out that there are no simply choices in the shitty situation that was left with Apartheid.

I am however convinced that the reconciliatory approach of Mandela played a key role in convincing the Apartheid regime to give up.

https://en.wikipedia.org/wiki/Truth_and_Reconciliation_Commission_(South_Africa)