Taking care of my elderly mother is a lot of work, and involves a lot of personal sacrifice on my part. I would not do half as much for a friend or aunt, uncle, or more distant family member. I would not do this much for a sibling, either, as they aren't helping much or at all with my mother (their step-mother). As far as elder abuse by family members is concerned, I don't know all the details of that, but I do know they cast a very wide net for what they consider elder-abuse. Letting an elderly parent take care of themselves when that is what they want can be considered elder abuse, as well as taking compensation from a parent for your time helping them. That is what I have read on the internet, anyway, an heard from a nurse when I first took my mother into the hospital when she had a fall. I had an infant and toddler at home at the time, but the nurse accused me of elder abuse because I didn't immediately stick my mother in a nursing home against her wishes. My mother still is living at home by herself with help for 1/3 of the day, and is doing amazingly well. Without my advocacy, I have no doubt she'd be dead right now, perhaps after going broke from paying $8000+/month there. She was in a rehab facility for a couple of months, and they aren't terribly attentive, gentle, or patient, to say the least.
So your point is everyone should have kids (and probably several to improve the odds) to take care of you when you get old? Despite any other misgivings about having children, nor any potential that you will be the one takng care of your kids still when you are old? I'm sorry, but among just my and DH's families, the stats would be like 1 in perhaps 5 kids would be geographically near AND not assholes/not problematic personality/not developmentally disabled/reasonably ok financially to do less than full-time work. Even geographically kinda close (like 1-2 hr drive away) would make daily care difficult or impossible, especially with their own kids whom they have to take care of them eventually. Never mind if they have any of the following situations: demanding career, financial problems, physical problems, crappy personality, trouble with the law, mental disorder, etc.
One in five might be generous, given all that, and five kids is a lot! Never mind that the only premise upon which you are having them is old person insurance...not very nice for the kids! Nor likely very successful.
If you had kids and then they helped you when you wound up needing it, great. But planning for that seems like a crapshoot. Like planning for a doctor child or football player or something.
I think the demands of modern work/family structure of the westernized nations, combined with ever lengthening lifespans, is just not going to support caregiving of the aged by their own family in most cases. Unless there are a lot of kids/households in close proximity to the aging person, available to split up caretaker responsibilities; enough money relatively equally distributed across the aging person and the caretaker households so as not to create extreme strain; pleasant, flexible, and mature relationships among all involved parties; etc, it gets real ugly real fast. I've seen this pattern on both sides of my family going at least 4 generations back...15-20 years of caregiving in several cases...it poisons otherwise good relationships among kids and parents, and among siblings.
Plus, families now have (generally) fewer kids, and kids are scattered across the country or world; more people are sole breadwinners, and HAVE to be working all the time to pay bills... they can't just give up income to care-give without derailing their own lives.
In the latest iteration in our family, my father is going downhill with physical and mental health problems. He lives alone in an isolated house in a small town. There are three of us daughters. I'm married, living on the other side of the country, and working three jobs. I'm also already supporting my mother (who at least was proactive enough to move across the country to be near me). One of my sisters lives on the OTHER side of the country, is working full time, just bought a house, and rarely has enough money to even buy a plane ticket anywhere. No help there. The third sister is only 4 hours away from Dad, but is just out of college, paying student loans, and working 2 jobs with zero flexibility. She can't afford more than a few days off either, or her life derails.
Luckily my father DOES have money (so far), which could be used to hire caregivers, assuming he can find any in his tiny town of 8,000 people. But did I mention he has mental health and anger management issues, so he often isn't even capable of consistently paying his bills, let alone dealing with caregivers? He will fight tooth and nail to stay in that house, or at least in that town, and even if we successfully arrange a caregiver, or he grants one of us control over his estate/finances, he's likely to drive away any hired help in a fit of rage.
So...He's most likely to die soon, alone, probably in an unpleasant, traumatized, and ugly way. There really isn't a lot we can do about it, so I'm not going to feel guilty, though I do of course feel depressed about it. I suspect this situation isn't all that unusual.
This anecdote is NOT a troll for pity or advice, but only to point out that although I admire those people that are willing (and able) to directly caretake aging relatives, I would never in a million years count on that from hypothetical kids of mine. Nor is it a legacy I'd want to leave them.
And it's going to be an ever bigger challenge for the country as the population ages, no doubt about that.