That's because Australia outsources resource extraction and gets hosed by the private companies, who extract the minerals and keep the lions share of the profit (and still whinge about paying royalties). The Arab countries use government corporations to extract their resources and as a result they keep most of the profits. Again, another issue when you dont strictly control lobbying/corporate political donations and allow interests groups with deep pockets to unfairly dictate public policy (like unions, mining companies, environmental groups etc)..
First of all, the extraction isn't outsourced. Nearly all workers and contractors in the Australian mining industry are Australians. It's the investment that gets oursourced (largely because there isn't enough funding available in Australia).
Secondly, the economics of oil and gas production are radically different to minerals extraction.
Saudi Arabia has massive, long-life known oil reserves and can operate on a massive scale.
Mining, especially somewhere like Australia, is completely different. The average operation is much smaller, has a lower lifespan, you need to spend (and risk) a lot on exploration, and even after you find something and spend the money developing the resource, there's a signfiicant risk that the resource base was overestimated or extraction/processing costs much higher than expected.
It's easy to look at the biggest iron ore operations and think the government should own them, but 1) This isn't the whole mining industry, 2) Iron ore wasn't that valuable before a few decades ago so a lot of this is hindsight bias 3) billions have been spent on exploration over the past few decades to allow current iron ore production rates to be what they are and it wasn't obvious that e.g. BHP or Rio were going to be the ones who made the most important discoveries originally 4) It wasn't obvious in advance that any given mining project was going to be particularly unprofitable
Your vision would require
A) The government itself risking $4 billion a year on exploration itself, which it is unlikely to do as well as private exploration companies for obvious reasons, like general government inefficiency, being pressursed into spending this exploration budget to "more fairly benefit communities" i.e. more equal geographic distrubition instead of what the geology and market conditions dictate, hiring or contracting people based on political considerations more than competence/cos effectiveness (e.g. maximising the use of indigenous owned contractors for its own sake), and not increasing or reallocating spending based on market conditions even if it means jobs are lost in a certain area, among other things. And more importantly, they have to pick which exploration finds get developed into mining projects, where all of the above concerns become 10 times as worse, because people will be angry if most of the mines are getting built in northern WA instead of other places, and people will demand that mines remain operational to 'save jobs' even if they're no longer profitable.
Or
B) Dictating that every mining operation in the country becomes majority owner of any mining operation in the country and somehow expect that this won't radically disincentivize private mineral exploration and development investment even though it means any discovery has only a fraction of the economic value it otherwise would have. And also hope that none of the above issues also come into effect (e.g. refusing to accept closure of unprofitable mines) from their majority ownership of these operations, which wold either mean government subsidising these operations (defeating the point of them owning them - it was supposed to make the government money) and would lead to value destruction, or you're forcing private companies to maintain unprofitable operations themselves, which would further disincentivise investment.
