In most cases, you don't need a camera lens protector for an iPhone. Like Rudegar, I have never used them for any of my phones. The iPhone 14's camera lenses are made from very durable sapphire crystal, which is designed to resist everyday scratches from normal use.
That said, the lenses aren't completely scratch-proof. Contact with very hard materials (such as sand, certain rocks, or other abrasive particles) can still leave marks.
A lens protector can provide some extra protection if you work in dusty or rugged environments or you're often around sand or construction materials. However, some aftermarket lens protectors can reduce image quality by introducing glare, reflections, or reduced sharpness.
For most people, using a good case with a raised lip around the camera is enough to help protect the lenses during everyday use.