> The future may reduce the economic prosperity and push humanity to switch to some different economic system (maybe a better system). Markets don’t want to accept that

I don’t understand what the writer means by “markets don’t want to accept that”.

Markets are fundamentally an expression of optimism, not pessimism.

> But stocks are insignificant in the vast perspective of human history, and even systems that lasted a lot more than our current institutions eventually were eradicated by fundamental changes in the society and in the human knowledge

Wealth creation (and at times, destruction) is as old as humans. We use our minds and our bodies to make more than what there was before, not merely taking what exists naturally without transforming it (adding value, i.e. creating wealth).

Stocks map to wealth, but they are not the wealth itself. They are a stand-in.