I wish Apple allowed no-charge IAP (it solves certain problems), but alas, the "Free" price tier does not exist in iTunes Connect for IAP. (As of a month ago at least, and I submitted the request to Apple to allow this several years ago).
What does that mean? Technology changes, so the definition of a current smartphone (current models, not old models someone still have in their drawer or dresser top [where my original iPhone is]) will change with that technology. Not so hard to understand.
I was replying to someone who claimed that if it downloaded apps, and a couple of other things, made it a smartphone. In fact, that very thought about the original iPhone came to my mind when I read his claim. Personally I would say that the definition of smartphone evolves with the technology.