Yeah, I just did a read on SWEAT's website & even a report by the SAHRC. I don't know why people think this, but not all sex work is illegal in South Africa. For instance, exotic dancers aka strippers, adult entertainers aka porn stars, are legal.
What is illegal in SA - & should be decriminalised - is prostitution. And I think this is where the confusion stems from, but people who engage in prostitution as the provider are increasingly called sex workers.
However, a prostitute(sic) while being a sex worker, is not the same as an exotic dancer, adult entertainer, or someone who runs an OnlyFans, who are also sex workers.