You are going down the rabbit hole of economics theory here... but anyways.
Money is made up and could be infinite if the government so decided, that is true. But in the real world you can't just print money (Mugabe tried that once) and there are things called budgets. X amount of dollars will be allocated within the budget to this type of thing and nothing more. X is a finite number whether we like it or not. The Penrith stadium getting built will be at the expense of other stadium and wider infrastructure projects, that is just a fact and is true of any infrastructure expenditure.
I personally believe that if this money is going to be allocated to stadium builds/upgrades then there are better options out there.
Not true. Besides look at what the banks and in particular the Fed has been doing for over a decade now with their quantitative easing program. More money(trillions) has been pushed into the system just to keep it afloat.
Look at the end of the day, if you have unemployed people, then you can issue more currency to create Gov or private sector programs and create more wealth for most people. When you run out of people to employ, that's when you ease off on issuing more currency so as the supply off money doesn't exceed the supply of labour. Generally labour is the barometer on how much money should be created. Contrary to their rhetoric private banks however don't care about inflation and print more then what is needed or much less depending on what their intended goal of the day is.
Why have we allowed this most powerful and important part of our societies to function and prosper to the private sector whos only mandate is to make profits for their shareholders? Can't see anything going wrong with that. No one is saying to just print money without purpose or reason mate. That is what banks do now when they want to save themselves or make off with our assets.
People really need to educate themselves properly on this topic and not just take what the banks spread as fact through their propaganda mouth pieces. Remember banks own everything and everyone, so they have a lot of weapons to make sure you believe their message.
We need to take back the power of issuing our own currency. Nothing will ever change if we don't and people will just keep spewing out the same line over and over again that there isn't enough money bla, bla, bla crap forever. Remember scarcity not abundance is the constant message. Keeps everybody in check and not demanding change or their rightful share. That way the people that are the beneficiaries of this broken and corrupt system keep getting fatter while the rest of us fight over the scraps that they give us.
The pie is massive mate. You just don't get to sit at the table to feast on it. You're on the floor like all the other sucker dogs waiting for a scrap or two to come your way.