Economics is a study of the allocation of scarce resources. How the resources are allocated can vary. Often, for the sake of efficiency, resources are allocated in free markets. Their trade is determined by prices which reflect their value at any given moment in that current context. This needn’t always be the case.
In a situation such as the 2020 pandemic, scarce ventilators needed allocation and money played no role. There were not enough for everybody; deciding to whom they would go is inherently an economic question. Economics is frequently our best means by which we can analyse cause and effect. If the ventilator goes here and not there, what happens? Improper allocation results in more dead patients.
In a world where no resource is infinite, our desires are of no concern. We only have options, which option we choose is often best influenced by economic thinking.