Who's going to change your diapers when you get dementia?
This a highly labor intensive activity – you can't easily “productivity increase” your way out of the problem, nor do there appear to be viable alternatives to shift this responsibly back onto individual families – if you think your kids are gonna' do it, ask yourself if they are going to be able to afford to leave the workforce for 5 or 10 or 15 years to take care of you – remember there's going to be a severe labor shortage, and they can't hire someone else to do it even if they want to.
Nor does it seem likely there are “technological” solutions, unless you are optimistic that robotics will soon have advanced to the point where they can perform such tasks satisfactorily.
Or, maybe we could “export" the problem by sending Grandma to Central America, to be cared for by abundent low-wage workers there, instead of importing Central American workers to care for her here? "Out of sight, out of mind”, as they say"?
This is just one example of the sorts of practical problems you encounter when you get the sort of ratios of employed to retired citizens we will be seeing in the nest 30 years, and to every one of them the the practical answer is that we are going to have to do something to change that ratio.
And if you have some suggestion other than rather large scale immigration, I'd like to hear it.
Now, these is noting in this view that supposes that we have to operate as we do at present , with any damn person who choses swimming the river.
But I just don't see how we can avoid large scale immigration if we want to keep this economy running over the next thirty years - in anything like it's present form anyway - without ruinous taxation of a relatively ever shrinking proportion of still employed workers.