Why do girls want to be my friend but never want to date me?

it seems every girl im attracted to and is single seems to only want to be friends. and then they go and hook up with my best friends. it seems im always the nice guy and never THE GUY. plz help im the most good looking guy im 5'11'' 214 pounds short hair and no facial abnormalities like big ears or nose plz tell me what i have to do to finally get a girlfriend.