Every capitalist economy deliberately keeps a substantial pool of unemployed workers in order to suppress wages and bargaining power. There isn't a lack of people to do care work, there is a lack of investment in people - and the devaluation of people and nature is a requirement of capitalism, there is no profit without it occurring somewhere in the equation. All of the concerns you've outlined can be nullified and then some by cutting out the tumors - billionaires, landlords, private banks, rent-seekers of all kinds - freeing up even more labor toward socially useful ends.

And billionaires understand this, which is why they promulgate the idea that maybe we just can't care for our elders and disabled anymore.

On the flip side, here in the US, the older generation is reaponsible for the fuck ups of the oast that got us here, and they are responsible for the ongoing issues the younger generations are experiancing trying to get decent paying jobs.

FYI, humanity cannot survive with just two people, either:

https://www.britannica.com/science/minimum-viable-population

Not really, no. Assuming those two people were opposite gender and able to procreate, they'd still only manage a few generations max before inbreeding made the species nonviable. https://en.m.wikipedia.org/wiki/Minimum_viable_population