No Knock taken.....Any Medic Unit can administer Cyanokit and sure you will see line medic units working in some interesting places, The difference is that the Rescue Medics are trained for, equipped and familiar with working in or in very close proximity to environments that line units are not trained or equipped to safely and effectively operate in.
This capability enables them to get the resuscitation part of the rescue/mayday/distressed member started immediately upon the patient being identified/removed. Truthfully you need them immediately assigned on any 10-75 or when the box is loaded up. The goal is to rapidly manage life threats that are best addressed sooner than later. Removing the patient to the ambulance before addressing life threats is never good for the patient. Unfortunately, in some but not all cases, in high stress situations the ambulance crew will look to get to a place where they feel they can manage the individual "better" and default to trying to get the the ambulance before starting substantive care. Plenty of videos on the internet showing just that.
Additionally, you can't do effective patient care while sprinting with the patient to the ambulance. Even when the patient is on a stretcher and being wheeled to the ambulance many times it's in such an uncoordinated manner that the care being administered is less than effective. Take for example cerebral blood flow and how it falls significantly when chest compressions are done while moving the patient. Ever try and keep an effective face seal on the BVM when moving to the patient ? Many of you here are likely aware of the challenges involved. The goal is not to see how quickly you can get the ambulance but rather how quickly you can effectively identify and address life threats. Sometimes it takes a little courage to manage the patient where you find them. Everyone wants to get to the ambulance but that's not always the best first option. Yes they need to go to the hospital but in an orderly, expedited well managed fashion. Medical management of the Mayday is something that has a lot of moving parts. It's not as easy as one might think. It takes training, practice and a complete understanding of ones role I the event. The FDNY has thankfully invested in this and has made great strides.