True, but it is stated that the data is retained only for 2 weeks. The app collects very little data and over such a short time period it can be considered quite a minimal privacy-risk.
You live in South Africa, so you're probably in fairly close proximity to a violent criminal... no app needed really.
This is a straw-man if ever I did see one. The president has encouraged people to use it, but there is no compulsion anywhere. No business, no transport, nothing is going to check if you have it installed. No force, just suggestion.
There is literally one reason for this app, to get alerted if you come into relatively close contact with someone who tested positive in the last 14 days, and to anonymously let others know if you tested positive. That's all.
Sure, COVID doesn't seem that dangerous, SA has a comparatively low death-rate. But as low as the risks are, they're not zero. So this sort of information is especially valuable to people with elderly or diabetic family members.
Disclaimer: I don't have the app, don't intend to install it because I'm just far too lazy. I also don't have any bluetooth accessories so I never switch it on on the phone anyway, what for. If I were out and about more often, and I had elderly relatives at home, I actually probably would install it.
IMO most of the response to this is just a knee-jerk against the ANC. Government suggested it, it must be bad. I can guarantee you that if Mother Theresa suddenly came down from heaven and took control of the ANC behind the scenes, and did everything morally, ethically, and logically correct, people would still **** on the ANC and government in general and find excuses to criticise.