Everyone’s degree of insulin resistance is different, so everyone’s carb tolerance is different. Genetic variation also plays a part, I’m sure. If you eat whole fruits (avoiding juice, smoothies, and pulped fruit), the intact fibre helps slow the rate at which the fructose hits the liver to something the liver can manage without damage.
(However, there was that executive at DuPont, who successfully lost weight on a low carb diet, but who would start to gain again, if he ate so much as an extra apple. I assume he was really insulin-resistant. This was one of the case reports written up by the DuPont company physician in the 1950’s and 1960’s.)