"hen that would mean there is an infinite amount of money to spend reducing very small risks." There is. But there isn't an infinite amount of stuff. And since

"hen that would mean there is an infinite amount of money to spend reducing very small risks." There is. But there isn't an infinite amount of stuff. And since to spend you have to have something to buy the spending stops when the real resource runs out. That's the actual limit - until you use some sort of power dynamics to start moving physical resources from their current uses. Hence the shortage of PPE at the start of the Covid crisis. All the money in the world; not enough masks to go around. There was "demand", but no "effective demand". Money is essentially inductively connected to the real economy, not directly connected. As an analogy in electrical terms money is apparent power, and the stuff it buys is real power.