Some councils also have data on their own websites, see for example the City of Casey (Melbourne) at: Explore — City of Casey's Open Data Portal
Many councils also have their own mapping websites, that which I live in (Mornington Peninsula Shire) has one of the most detailed local government asset mapping websites in Victoria with much park / street furniture and the like; I’ve got a list of these at: Spatial Sciences - Mapping links
A number of councils in Vic / NSW / WA in particular also are invovled in the A-Spec program for recording asset data - https://www.a-specstandards.com.au/ - although I have no idea if this could be used on OSM.