Wondering About MRIs

How can all 3 of these things be true:
1. MRIs are super expensive to get.
2. MRIs don’t require a doctor or other very highly trained operator.
3. Many MRIs don’t run 24 hours a day.

I mean if the cost of MRI is about amortizing the high cost of the machine then not being open 24 hours/day is a huge loss of profit to the operator. Given that major metropolitan centers have multiple MRI machines (including ones not connected to hospitals) it can’t simply be that demand is limited by geography (i.e. one could save money by buying fewer machines and running them all night).

Even if MRI operators need to be more highly trained than I suppose note that the cost of an MRI is orders of magnitude beyond that of similar time with a MD so the cost of paying the operator is a small fraction of the total charged cost.

Is this some kind of huge economic failure induced by insurance?