circedone Again generally its true that intact men dont need lube to engage in sexual acts, however similar to how sometimes women need lube despite having glands specifically built for lubrication sometimes intact men also need a bit of luberication, bet it natural or artificial, or intrinsic or extrinsic. Aslo circumcised penises are even more dependant on lube than we are so even if some of us might need a little bit once in a while, the enhanced functional capacity of foreskin still stands.
Also you have to remember that the mechanical action of the foreskin and its ability to make do with little lubrication and its ablility to potentiate the effectiveness and efficiency of any lube that is used on it is even more important than the lube itself. These effects cannot be replicated by any circumcised penis no matter how much lube you apply to it.