ABCs are not just for the "the very small percentage who need life-saving interventions", unless you think that "A" just means "do they have an airway?", "B" means "are they breathing?" and "C" means "do they have a pulse?". If you expand what you're thinking about when you think ABCs, then yes, they are definitely the meat and potatoes for 99% of patients, actually.
Airway - do they have one? If yes, are they at risk of losing it due to the MOI/NOI? FBAO? Epiglottitis? Anaphylaxis? Unconsciousness leading to obstruction by tongue? Angioedema? Do they need suction? OPA, NPA or Combitube?
Breathing - what's the general rate, quality, and work of breathing? Breath sounds? Pain upon breathing? Coughing? Blood or fluid being coughed up? History? Medications? Chest movement? Percussion? Trachea position? Paradoxical movement? Oxygen?
Circulation - general pulse quality and rate? Bleeding? (either related or unrelated to trauma**), Skin color, temperature and condition? Blood pressure? History? JVD? Shock?
I know that this bleeds the ABCs into the rest of your assessment, but when you think about the vast number of conditions that involve mostly one of the ABCs, it makes sense: asthma, pneumonia, stroke, MI, a broken ankle, some frequent flier with a cough... serious or not, an ABC problem, no matter how minor, is often the root of a patient's problem.
One time I provided care for a man that clearly did not have a life-threatening problem at all just by looking at the ABCs... he came up to me and calmly told me that he had accidentally cut his finger (okay... the As and Bs seem good) but I looked at this finger and it was indeed bleeding (uh oh... C problem) so I put a bandaid on it.