Speed changes the story
Carbohydrates do not all reach the blood at the same speed. A drink, a soft sweet, cooked rice, whole fruit, dal, and a mixed meal can create different digestion conditions. The glucose curve reflects both the amount of available carbohydrate and the speed of absorption.
Fibre can affect that speed by changing food structure, viscosity, water movement, chewing time, and enzyme access. This does not make sugar harmless, and it does not replace medical care when glucose control is a clinical issue. It simply means the physical design of a meal or product matters. In nutrition formats, fibre is part of how the system behaves.