The ‘Smart Phones’ tend to not be very good phones. I can see a divergence back to old text and talk phones and separate tablets or wearables for data.
lets just correct that little goofball generalization.
Phones in general often have poor receiver/transmitters. Many consumers don't bother to research that part of a phone.
For people whom that part of the phone is critical to {people in rural areas, contractors who work in metal buildings) there are websites which measure that.
You could more accurately say that Apple has never put much work into that part of their line of phones. Apple has never been the whole market though.