I read somewhere along the line that they tried this with men early on and one man died in the trials. One man. So they then turned their focus to contracepting the female. I don’t recall how many women died before they got it ‘right’.
Pope Paul VI’s much maligned and generally despised encyclical, Humanae Vitae was prophetic in its foretelling of precisely what has come to pass since the sexual revolution started. It started some 38 years prior however, since before 1930 no Christian denomination embraced artificial contraception.
Birth control for men is supposed to be very complex.