The author conflates sugar/honey etc (pure carbs - glucose, fructose) and artificial sweeteners like stevia and erythritol which don't have any effect on your blood glucose and really are completely different. I fully agree with the premise of minimizing sugar consumption but I don't think encouraging people to avoid certain artificial sweeteners like stevia etc is helpful - and in fact it's hurting because certain products with these non blood glucose contributing substitutes help people avoid sugar.
Note that although artificial sweeteners like stevia and erythritol don't raise the blood glucose at all and have GI index of zero or near zero - some artificial sweeteners actually do raise blood glucose, like maltitol etc, and these sweeteners are unfortunately often found in sugar-free candy. You can try a web search for "GI index artificial sweeteners" to see a list of sweeteners that have low GI score.
Something else to keep in mind is that over consumption of very carb heavy products like bread or pasta will have the exact same effect on your blood glucose as just eating sugar.
Note that although artificial sweeteners like stevia and erythritol don't raise the blood glucose at all and have GI index of zero or near zero - some artificial sweeteners actually do raise blood glucose, like maltitol etc, and these sweeteners are unfortunately often found in sugar-free candy. You can try a web search for "GI index artificial sweeteners" to see a list of sweeteners that have low GI score.
Something else to keep in mind is that over consumption of very carb heavy products like bread or pasta will have the exact same effect on your blood glucose as just eating sugar.