Propaganda War against retired people?

Some economics gurus here in Estonia and elsewhere are predicting that the pension system existing in European countries is doomed. As there will be less and less working age and really working people and more and more elderly, retired people, this seems to become an intolerable burden to the working people, i.e. taxpayers. Well, this is not the main problem. Let's make a thought experiment: there are no workers at all, the intelligent machines, robots make all the necessary work. Who will then pay the taxes, where does the money come from? This means the idea of work and taxation must be reconsidered. The GDP or in whatever way we measure the wealth of a nation has not diminished, there must be some ways to redistribute it without extra taxation of the wage earners and businessmen. For example the "Tobin tax" or something similar.

The real problem is not the ratio of people working and people retired but the rising cost of taking care of the elderly that is rising with the rise of average age. No easy solutions here. The aim must be to find ways to find efficient ways of keeping aged men and women healthy, to fight such deseases as Alzheimer, Parkinson's disease, etc. This is a difficult task, but not a mission impossible.