The price is signifcantly different, and that is why wild areas will never have not even close number of visitors. 99% of interested hunters will never visit wild hunting areas due to budget constraints
Next, game quotas in wild areas are much more limited, so number of trophies exported will never come even close to south african export.
But exactly for this reason South Africa has a great place in Safari industry, to be affordable for all classes of hunters.
In last 100 of years we as a hunting community lost about 50% of huntable countries in Africa (and wild areas, we lost even more. Becasue even in huntable country hunting areas are in limited numbers and those countries are not "full country" huntable)
So, I think that if this trend continues, very soon, in next 100 years, we might easily remain with game farms to hunt only. (and international regulation wise - maybe)
Other value of game farming is possibility of reintroduction of endangered species to game depleted areas in the future, or even to national parks.