A EMT is in no way qualified to handle emergencies on their own (and yes,I know their curriculum very well). And no, the majority of ambulances are not paramedic-staffed in the US - Actually only 25% of all licenced providers are Paramedics and there are large areas which have only BLS available in a reasonable timeframe. Or no EMS at all, as ambulance services are NOT an essential service in most states. (Only 11 States see it differently).

So no, not even remotely "most ambulances" are paramedic staffed. Mathematically impossible.

Besides: The shortest current timeframe in the US for paramedic training is 6 months.

That is incredibly short in international comparisons, especially when one does compare it to the skills allowed with it.

Comparison: Australia: 3 year bachelor degree to even make it on a Emergency ambulance (not counting very rural WA&NT), a master degree for the more serious skills.

Germany: 3 Year apprenticeship to be in command in the ALS ambulance, but emergency physicians are tasked to more serious cases

Switzerland: 3 year degree, emergency physicians being somewhat common, though, often additional nursing and critcare degree required for more serious cases.

Hungary: 2 Year EMT course for EMT, 4 year Bachelor for Paramedic

Poland: 3year Bachelor as minimum.

South Africa: 1year minimum for the entry, 2 year's for most jobs, 4 years for paramedic.