There are a lot of reasons to take a knife. One hunter said he only used a blade at the dinner table. Another used a knife and his fire starter to build a fire when his PH and trackers left him alone with the carcass of a buffalo. In the dark of that night, he was glad he had a blade to make tinder and get the blaze going.
Bring at least a multi-tool and a folding knife for camp chores. If you want to help out, bring a machete or a saw and a gut hook and a skinning knife.
From the airport to a tented camp in the Kalahari, somebody will be there to take care of you. Or maybe they won’t. Many of us feel unprepared without at least one knife on hand. To my way of thinking, the bush is not a place to be unprepared. I take my best rifle to Africa and blades I can depend on.