Depend on them for what, the cost of a bowl of rice? What is it exactly about 80 year olds that will collapse a country with a brutal government like China has?

Depend on them for retirement, given that most of their wealth is tied up in their busted real estate market.

You think that a country that has a strong cultural history of venerating their elders is just going to pivot on a dime and decide to put grandma and grandpa onto an iceflow and cut them loose? Those elderly out in the hinterlands are also the people who raised a large fraction of the youth population while their parents were off in Shenzhen pulling shifts at Foxconn.

The other thing to look at in those population distributions, besides the upside-down age distribution, is the absolutely pathological gender imbalance. The number of surplus males under 30 should be keeping Xi Jinping up at night because if there is anything that is going to trigger another revolution it is tens of millions of disaffected young males migrating across the country who eventually get fed up with what they perceive as a dead-end future.