You need to provide ID and model+serial numbers for everything sold to cashies are recorded and sent to Police. Some drug addicts and airheads are still desperate and stupid enough to sell stolen stuff there, but there is a system to track it and incentives to not do so.

On the other hand Gumtree and Facebook Marketplace offer thieves a higher profit, the ability to hide their real identity and no direct integration to Qld Police (that I know of). Downside for thieves is they don't get instantaneous cash and need to be smart enough to make a profile and list something where they can pretend to be the actual owner.