In Australia a mostly open, sparsely populated, continent sized island with vast amounts of sun wind and hydro, with people mostly gathered in a small band of the coast on one side (and still even then needed 1/3 of total generating capacity backed by fossil fuels).

It's great that oz can maybe get away with almost entirely renewable (maybe, that simulation is essentially just multiplying current generation by a large number, adding some storage and saying that mostly takes generation above demand, it doesn't do any sort of analysis of when where or how that energy is generated or makes its way to the sources of demand), but it's not a model for the rest of the world.