the centre floods on occasion, but to permanently hydrate the interior would likely irrevocably fuck up huge amounts of the country.

not to mention that Lake Eyre and all the other lakes in north SA/west QLD are salt lakes that only fill on very long cycles in specific conditions, so just pumping water into them year round is probably gonna start a Salton Sea situation sooner rather than later. but following that, the flow on effects to climate cycles from rehydrating the Simpson desert could be really fucked (because it would be super unpredictable)