Birth control made those old rules obsolete. That's just not true. But these practices were devastating for individuals, families, and society. Women were treated as disposable objects, mere toys for sexual pleasure, to be discarded when passions waned. It's really just a private matter between us.
Sex is intensely private and personal, but it also has deep moral and social dimensions.
Sex works as a primary bonding agent in families and the family is the building block of society. Sexual rights and wrongs influence the health and happiness of individuals, families and neighborhoods. That's why sexual behavior has always been the subject of many civil laws. The Church, of course, wishes to safeguard the family and society. But, more than that, the Church wishes to safeguard your relationship with your future spouse and with God.