Since I finally get to look at this stuff from the other side in the ED, I can share some of my experiences. I remember how stressed people (myself included) would get over whether or not certain patients were ALS or BLS patients. Was their pressure too high for an EMT to ride it in? This patient is concerning for a cervical fracture--is that ALS? People would get in trouble for 'inappropriately' BLSing syncope. People would wait on scene with stroke patients so ALS could ride it in.
Rest easy, because 90% (or more, probably) of the time it makes absolutely no difference. Hypertension? Doesn't matter. Stroke, assuming no airway compromise? ALS saves nurses the 30 seconds it takes to put in a line. I remember medics rushing in a patient who they described as a "really interesting case" who was discharged two hours later. Meanwhile, private BLS units who may or may not have actually taken vitals would drop off floridly septic geriatrics from the nursing homes who would end up in the ICU.
There are certainly patients that benefit from ALS--certain respiratory emergencies, early recognition of STEMI, status epilepticus, hypoglycemia--but there are a large majority of patients who aren't going to need or benefit from ALS procedures. There's also a lot of controversy on whether certain procedures are beneficial in the long run (prehospital intubation has been the big one for the last decade or more, ALS trauma care is another).
All of that being said, the most important thing a paramedic brings to the table vs an EMT is education, understanding of pathophysiology, and experience, so I strongly disagree with the idea that we should lower EMS education any more than it already is.