Why didn’t a lot of WW2 aircraft have front landing gear?

most WW2 aircraft you see usually have two frontal gear and a rear wheel which sometimes retracted or not. My question is why didn’t they do the landing gear set up of something like the B-25 or A-20 with one wheel on the front and two under the engines or middle of the airframe? Id they didn’t wouldn’t it have helped aircraft not have the possibility of falling forward or help with a easier landing?