Why might the W.H.O. recommend rationing healthcare to treatments that cost less than three times annual GDP per person as opposed to providing as much treatment as is needed by a patient, regardless of cost?

Putting a Dollar Value on Life? Governments Already Do The World Health Organization suggests governments pay for treatments that cost less than three times a country’s GDP per person for each year of good health it provides. The W.H.O. considers treatments that cost less than the annual GDP per person to be highly cost effective.