>>12699457Originally marriage was invented by women as some sort of social contract where the man would help her support her children
Ensuring a relationship was necessary to ensure the survival of the next generation despite all the hardships like dangerous animals, famine, etc
In our modern times, that kind of social contract is more flexible since society can provide a fair part what's needed for the next generation
Additionally, the development of birth control made it so there are much less risks of getting unwanted children
Humans have acquired the luxury of recreative sex, something their ancestors couldn't afford without putting the future of the next generation at risk