In the days before welfare states, occupational pensions and state run old age pensions, it was quite common in most of Europe for the elder generation when they were handing over the responsibility for running a farm or a business to their son and daughter-in-law, or daughter and son-in-law to have a legally binding contract made out, stipulating where the old people were to live on the farm, the amount of food, and firewood that the son would provide yearly.
There is even said to be one such contract in a Danish museum that stipulates that the old folks had the right to use the farm privy. And if you are wondering where else they could have gone, the answer is either the unroofed farm midden in all kinds of weather, or the cow byre and hope the cows didn't need to wee while grandpa or grandma were squatting behind them!
Now-a-days I agree it is each generation's responsibility to try and put money aside for their old age, but we may all still need help with tasks that are beyojd our physical strength as we age. It is nice if our children offer to help, but I agree, we cannot expect them to, or take it for granted that they will offer.