You don't need McAfee on your iPad. However, if you're using your iPad for work and connecting to your employers servers, they may require you to install an Enterprise app like McAfee EMM.
From what I understand the McAfee product for iPad and iPhones has nothing to do with protecting against virus and sort. It is a tool that allows a user to restrict what is accessed through the browser on the iPad. Would be a good tool if you had young kids who used your iPad frequently.