You can't buy an iphone with this functionality, and many people are locked into that walled garden for a lot of different reasons.
Usually, in consumer electronics, the unencumbered market tends to gravitate toward what people actually want to buy. Totally possible this could be an exception to the rule, but I doubt it.
In the absence of such phones, I compromise on adding a cover.
It's an extreme example, and way too bulky for most people, but the point is: "rugged cellphones" absolutely exist.
Also I don’t need fully ruggedized. Just enough that a cover would be superfluous.