But colonization certainly isn't more better. The aftershock of colonization is greater than any technology or economic growth that could be brought to the colonized place. The aftershocks of colonization cause hurting even to this day.
South Africa would've modernized at it's own pace. This is the best scenario for any civilization. If South Africa modernized at it's own pace, even though it would take forever, it would still be better off than being colonized. Colonization creates skepticism of modernization since the people of the formerly colonized country would associate it with imperialism. If it wasn't colonized it would view modernism more nicely.