It's never been specified. Themyscira never across as a money based society anyway. More like Star Trek style utopian society 'we've moved beyond the...
Or how about the Goddesses all being loyal to Gaia and acting as her agents and only pretending to be loyal to Zeus? That was a strong implication in...
The way I see it, at the time DC was going to get rid of their legacy heroes and that would have meant losing some gay characters like Obsidian/Todd...