Post doesn't tell the whole story.
From the article:
Only 59% of South Africans are willing to move to another country for work, which is down from a 72% willingness level in 2018.
Young and highly educated South Africans aren’t willing to move abroad either – only 56% of young people and 61% of highly educated people in the country said they would be willing to relocate right now.
(my emphasis).
Also, there are only 1400 south africans sampled in the survey.
Speaking from present experience, emigrating RIGHT NOW is a real mission. On top of all the other "usual" stresses you'd have to deal with, you have uncertainty around flights, quarantines, self isolating, lockdowns in destination countries that make getting some things done really difficult, delays with documentation processing, economic uncertainty in your destination, exceptional difficulty in finding work unless you're very lucky or very special...
I bet if the wording was slightly different and didn't focus on "right now" but rather "in the next couple of years" the results would be significantly different.