I'd like to see an accounting of the real resources (not money) that elderly require vs children and young to middle aged adults. I'm suspicious because it sounds much like the undue burden tripe you hear about disabled people.
At least in the US, expenses in later life seem not too bad, until the last 3-5 years--at which point healthcare cost absolutely blows everything out of the water. Like, more healthcare cost in one week at 85 than an entire year at 50. Especially once a person is unable to safely walk to the bathroom or prepare a simple meal without falling. Meds, ambulance transport, non-emergency wheelchair transport, rental of various equipment, home health aides, physical therapy, speech therapy, rehab or nursing care, palliative care. The costs are just stupefying.
Edit: I've replied mostly along the lines of the financial costs, but the human service component is by far the largest part of it, that's the main resource consumed.
I was thinking more along retired or semi-retired. But yes end of life is a thing. Even then people 'sounding the alarm' about the ratio of workers to retirees 'plummeting' are way overstating things. Over the next thirty years the percentage of people over 65 is going to double and then level off.
The source of the panic is the 'exponential growth forever' dingbats being confronted by a reality they don't like.