Really,
There is a "global pandemic" which has suppressed pricing on many routes which has in return made many award tickets non affordable vs a cash price.
In OCT 2019 OW tickets were about 300-400 [if I call recall correctly], I used 8k UA for a OW on SA.
CPT-JNB has usually been a cheap cash route where regular advance cash tickets has not been worth using award mileage for.