It’s also an absolute availability issue. A hospital has, in the near to intermediate time horizon, the staff that it has. So dedicating staff in such ratios make them unavailable to other patients, so triage considerations come into play.

Nurses are not an infinitely fungible commodity.

No, but a significant cause of current staffing shortages are stagnant wages (especially for non-travel nursing roles).

Hospitals paying decent wages to full-time/permanent staff would go a long way towards solving staffing shortages.

Staffing and cost are related, but there are staffing requirements that no amount of money thrown at them can fix.