TIL... . nationalmap.gov.au is/was an open source TerriaJS instance delivering all kinds of data via open standards in a single space.
The digital atlas of Australia is based on proprietary ESRI services. Colour me disappointed, not surprised
The strategic question being: why develop a new digital atlas if the old one was not used?
Personally I would have chosen to keep developing an open platform, especially in current geopolitical light.