There are two huge illusions that have complete disconnect w/ reality as lived by people and that feed two literatures.
1) The idea that people will suddenly turn become altruistic and not self-interested which feeds the idea of Kantian socialism.

2) The idea that people's needs are limited or can be reduced (willingly). It feeds the idea of degrowth & ecological Arcadia.
What is bizarre is those ideas are arising at the time of greatest commodification & role self-interest & desire for wealth ever in history.

In the past such ideas would lead to the creation of religious movements. But since nowadays creating new religions is not very fashionable they spill onto millennial ecologism and Kantian socialism.