South Africa is going through a very bad phase right now, with increasing number of infections and deaths, so the reluctance from the part of the Australian side to tour that country is perfectly justifiable. The South Africans are not very happy about it, and understandably so. The Australian tour was their chance of getting the finances back on track, and now that is gone as well. They have the option of traveling to Australia, but then the TV rights will stay with CA rather than CSA.
@Sithara007 it’s a sad decision for cricket fans because I was really looking forward to this series, but sadly one cannot do anything about it. Another option for them was to host the series in Dubai like Pakistan did, and then split the revenue with each other.
Source:
https://www.quora.com/Why-does-Pakistan-play-cricket-only-in-Abu-Dhabi-as-a-mutual-venue
You are right, Dubai is the most admirable place for cricket because when there is any risk in specified countries most of the countries will decide to conduct the cricket matches in Dubai and they will share the revenue, it has already happened many times in the history.