No, it's about the scale of society and how we support ourselves in retirement, though. See, if retirement funds rely on, as the guy above me says 1. Companies underpaying their employees and 2. Governments taxing a group of more people in the below generations than there are to support in the top - then those are unsustainable sources of retirement comfort.

So what would be sustainable? Well historically, and in some countries today, old people need family to support them into old age. You would need either your own kid, with their own house big enough for you, or a rich little nephew with a house big enough for all you and your siblings to live in while retired.

Or... We just do the decent thing and take care of non-relatives. To ease the load on, say, retirement homes, we'd need to agree across society to bring the old people into communities of younger adults, and those younger adults would need to check on them regularly.

Sice this requires a community binding together, you might call it "communism." Though it isn't necessarily Marxism.