Antler is harder than just about any wood going. I don't know about things like azobe and lignumvitae but it is harder than box wood. Face it, if stone age man could have used bits of oak for knapping, they would have done! If modern knapping teachers could get students using wood, they would have too. Also, antler has a couple of functions, both as a pressure flaker and as a hammer. For the hammer, moose antler is preferred due to its higher density and overall mass. For pressure flakers the usual alternative and probably better material is copper rod in a wood handle. You probably could get wood to work, but not consistently or over a longer time. Why handicap yourself like that?