States have more and less sane approaches to this. Obviously, many things are not as clear-cut as beheading. But there are states that allow EMTs to make a field declaration, depending on specific guidelines, and possibly with the requirement of contacting a doctor to describe the situation and get their permission to terminate resuscitation efforts.
While an EMS may not be able to sign the death certificate, they are quite able to say in cases of major trauma or obvious rigor that the patient is exceedingly dead.
[1] https://file.lacounty.gov/SDSInter/dhs/206332_Ref.No.814,Det...
On the face of it, it appears to penalise those who can't afford to get it wrong which feels morally bankrupt.
Economically not rich.
Morally bankrupt.
Some of the world's most advanced western countries that profess freedom and democracy across the globe.
Plus, it is not really a good look for paramedics to be leaving a dead person.