There have been literally dozens of studies done in the US on RSI, with most showing no benefit, and some showing increased mortality.
Sure, if we staffed ambulances with anesthesiologists, we'd probably have better outcomes in the US, too. So I suppose you are right that the problem has less to do with RSI as a procedure, and more to do with RSI routinely being performed by individuals woefully unqualified to do it.
The biggest problems I see are:
- Paramedics being taught that everyone whose had their bell rung needs to be intubated, and that prevention of aspiration (which usually doesn't happen on its own and when it does, actually carries a very low risk of mortality in young, healthy patients) is worth any risk to the patient, and
- Lack of basic airway skills. Paramedics simply don't know how to use a BVM and suction, so they aren't confident unless they have an ETT in place. When the only tool you have is a hammer, everything starts to look like a nail.