For example lets say we got rid of the work and holiday visa and drastically reduced the number of skilled migration visas, etc and instead we made it easier and more attractive for foreign investors and business people and wealthy pensioners to come and live in Australia. We could replace a lot of workers with business people and investors who create jobs instead of competing with locals for existing jobs.
This is the neo-conservative fantasy that if government just got out of the way and let people with money do whatever they liked then everything would be great.
There are four factors to production:
Labour
Land
Capital, and
Entrepreneurship
"Let's get all the rich people to come here" is not a plan, it's a small part of a very complex system that requires equilibrium to function properly. You can't give capital free reign to go wherever it likes without extending the same right to labour, otherwise the economy becomes unbalanced.
It's not like we don't have more pressing problems in the other areas either: the Australian definition of "entrepreneurship" has basically become a a case of buying an investment property, taking a tax deduction on the holding costs, flipping it to someone else a few years down the track and taking a tax deduction on the profit.
Enacting protectionist labour policies isn't going to help with the way we mismanage land and enterprise incentives. For example...
For example Australia lets in all these foreigners but our infrastructure is not keeping up with population growth.
That's our own stupid fault for not managing our infrastructure requirements very well. Shutting down the free flow of people is treating the symptom, not the cause of the problem.
How about for example we put a special type of investor subclass visa where if a foreigner can pass a police check and invests $1 million AUD into approved residential property development (I am sure property developers would quickly assemble funds/schemes for them to invest in) or into a government public private partnership infrastructure investment fund, or an approved tourism or agriculture business, etc then they get automatic permanent residency. We could even give them tax breaks for their investments.
We do exactly that already.
You start out on a 188 sub-class visa and then, depending on your situation, you can migrate here permanently e.g. 888 visa.