You think money only buys physical things? You fundamentally misunderstand what money is. Money is a promise. You can get someone to do anything for money. If you have enough money, you can get anyone to do anything, if not directly, you can pay someone to use force to get you to do it. Money is power. Concentrated money is absolute power.

Settle down cowboy, it's just optionality. You have to exercise that optionality to realise any power. You have to spend your money. Money can't buy everything. Money can also buy anything.

You presume money is constrained by the state. When you have enough money, power functions in the opposite direction.