They live in a socialist future without the need for money or population control. A world in which any 'thing' made from matter can be replicated from energy, and in which energy is cheap, plentiful and made very simply, by combining an infinite supply of space-collected matter and antimatter, in a chamber made from abundant and freely available crystallised dilithium. Their ships travel through sub-space destroying its fabric as they pass-by (see TNG episode.) Really, what could possibly go wrong with this ideal world?