What is new is that the elder people now need a greater level of care, for a more protracted period. That's new. In the past people who couldn't care for themselves rarely lived more than a decade. Now it is not unusual for such a person to live many decades. It isn't everyone, nor all old people, but it is a rare family that doesn't have a grandparent in need of 24/7 presence. The primary carer then needs relief. So you've got at least two or three people who are not able to alter their living situations without 'abandoning' the elderly relative.
Conversely in china, some young women are not getting married because they do not want to be roped into caring for their in-laws too. One of my Chinese students admitted that she was desperate not to return to china after graduation for fear of being locked into caring for her grandmother. Should she marry here, she would then be under pressure to have her grandmother move in. Her goal was to stay single and in school as long as possible. It's harsh, but she didn't want to be married so long as her grandmother was still alive. Marriage to a Chinese boy would only compound the problem as he would likely be in the same boat.
