that Bitcoin can actually be the solution to fixing the money, that's if you deem it fit to conclude that there is something actually wrong the monetary system 😁.
Money does not exist. All we have is currencies. There is also bitcoin which is a currency that can become money.
You also don't fix money (which is a tool) as the thing written on that tshirt says. You can use the tool to fix something else.
What needs fixing is the monetary system as you said. But that problem is not new and doesn't belong to our lifetime as the tshirt suggests

It's been going on for centuries, ever since they made the first currency that wasn't backed by anything and could be printed unlimitedly (can't be store of value hence is not money).
Fixing it is not easy either. It affects all aspects of society and most importantly there is no solution or alternative for the existing financial system. As I said, even if Bitcoin becomes money, it still is money not the solution to the monetary system problems.