But that's the trick, it's ALL spells.
Spells are what they use to cover 90%* of magical effects. It's why many invocations end up being access to a spell (slow, bane, mage armor). It's why a robust psionics was abandoned for psionic spells and subclasses. Spells are a known quantity, an understood mechanic, and an easy way to expand the game later. In short, they are the hammer WotC has elected to use, and everything else is just a nail.
If it helps, think of spells akin to 4e powers, save they are explicitly magical.
And feats will cover the rest.