You make a really good point, that older people typically tend to have some sort of investment/responsibility that gives them purpose and a reason to keep going, whether that be children, taking on the care of another family member, or a busy and fruitful career. They feel that they have an obligation to stick around for these reasons, especially when they have put a great deal of time and investment into these things.
I think there is some kernel of truth to the fact that keeping oneself busy, whether that's with child raising or something else, is a necessary driver to keep one plodding through life. When you are unable to handle such responsibilities, I believe this is when the cookie crumbles for many people, because we need distractions and obligations to keep the torturous thoughts at bay.
It doesn't have to be children, but that tends to be the case. A lot of older people receive support and a sense of meaning from their children and other relatives. Personally, I am against having biological children in my own situation even if I was able, because I feel like it would be selfish and morally wrong. There are a lot of hereditable diseases in my family which I also picked up, I don't have the means or capacity to provide for a child, nor do I have the necessary community and village that is key for raising a family. Plus I am way too traumatized to handle all of the invasive and demeaning medical crap that comes along with pregnancy and childbirth.
As a young woman, there is quite a lot of pressure to eventually "settle down" get married and have children, even in countries where women are statistically having fewer and fewer children with each passing year. The lifescript you're 'supposed' to follow is a very heavy weight hanging above your head at all times. Frequently you will be told that you must accept the role of mother and wife eventually, or you're going to die washed up and alone. This exerts great pressure on a young person, especially if you are struggling socially and financially. There are exceptions to this rule, but many men (and women too who are dead set on things like IVF) will view you as a means to have children, and will no longer love you if you can't provide that. This has been a very hard pill to swallow for me.
While it's not my 'main' reason for wanting to ctb, so to speak, getting older and watching everyone I've grown up around die, then having nothing to fill those gaps is certainly a factor in why I'm just completely done with everything. I'm expected to grow old, and take on more and more responsibilities, while having no support or ability to do so. Most of my relatives are dead and I have no super close friends. I'm chronically ill and have PTSD, I can barely do anything as it is, and men expect me to become a housewife and raise children?
There is definitely a gaping hole in my heart because I have no family and am going to spend my entire life perpetually alone, but I wouldn't be a good mother. It really hurts to see loads of people my age (mid 20s) entering happy marriages, doing loads of traveling, baby announcements, huge family photos, career successes etc when I don't have shit and never will. I think being a younger person and seeing what the future holds for you can be extremely damaging to the psyche.
