That can easily be balanced via legislation. What cannot be balanced is one partner having to take on all the health risks and lifelong consequences of childbirth and breastfeeding, etc.
The net result of this is that men are more likely to die any given year during their careers and have a life span shorter by several years than women do.
Sure, but let’s be careful not to cherry pick the statistics. It’s still true that the average life expectancy for men is about 5 years shorter than women.
I notice that there are attempts in our society to balance some areas of risk but not others. Breast cancer funding is much greater than prostate cancer funding despite the latter killing more people, etc.
Good thing it's opt-in. Why would you want to legislate opt-in behaviour?