but as it's a piece of metal, it's not going to suddenly snap. Metal doesn't do that.
Apparently you don't know shit about metal, metal fatigue, metal corrosion, or metal failure modes. Metal can and does snap. And well for example it doesn't even tell the full story. My breaks totally and instantly failed on an old hillman hunter 1975 car when the *metal* hydraulic line burst.
A budget is just a method of worrying before you spend money, as well as afterward.