1) If you add up all the gains from mining, and subtract all the costs, you think this number will be greater than zero?

2) Do you or do you not think the number of miners will ever reach zero? If not, why are you describing what would happen when there are zero miners?

This isn't some electrical system, it's a real life economy with real scalability limits. No one cares about imaginary chalkboard economics - it's that same kind of thinking that predicts all rational actors will hoard a deflating currency.