You touched on a major cultural conflict that exists in the west today - the competing interests of individual freedom and sustaining the society. Many old trad

You touched on a major cultural conflict that exists in the west today - the competing interests of individual freedom and sustaining the society. Many old traditions that seem cruel or anti-freedom were/are really there to keep the society existing. Marriage and staying married is probably one of them for reasons you identified. Western society is already collapsing (birth rates below replacement level), perhaps partly because of easy divorce and other traditions being lost. Another reason may be that most young men are unattractive to women and most old women are unattractive to men. So without any stable life-long partnership, people would make the most of their value in the attractive part of their life and leave the other part missing out emotionally (for men) and economically (for women) which probably isn't good for anyone.