Temba Bavuma is not a T20 player and the stats show for it, yes he may be a good test player but he is terrible in the shortest format,  South Africa has some really good players like Heinrich Klassen and Reeza Hendricks who are sitting on the bench, both these players deserve to start ahead of him, especially Reeza Hendricks who if we look at his form this year compared to Bavuma's it's so obvious who should be starting.

Temba Bavuma in 2022 T20Is:

10(8); 35(30); 8(10); 8*(11) - Retired Hurt; 0(4); 0(7)

Total: 61 (70), 12.20 Average, 87.14 SR 

Reeza Hendricks in 2022 T20Is

4(3); 23(20); 57(33); 53(32); 70(50); 74(53); 42(40)

The only reason Bavuma is in this team is that he is the captain and nothing else in a world cup it's important that you Play your best team to ensure you have the best chance of winning and for me the best chance we have is that we play Hendricks and drop Bavuma.