There is nothing wrong with functionality especially of round door ones that give leverage to be applied on a door. This means that you achieve less leverage and ensure that you achieve the best door assembly that is also affordable.
The reason that these doorknobs are round and large is that these were designed to make a large room appear cozier and create an optical truck that brings the ceiling height down. The door handles may seem to be fitted higher than usual ranges to follow the theme.
In most of the cases, the door set which is placed in the inside of a door and controls the door latch and these can be two sizes i.e. 2 - ⅜ inches and 2 - ¾ inches. All these doorknobs will work in these ranges.