The big advantage of low carb diets is that they lower blood sugar dramatically, even for people with Type 2 diabetes who have been running very high blood sugars for years. They can utterly transform their health, and because they make such a big difference in how they feel, people with diabetes are able to stick to these diets much better than most other people who try them. I have friends who have been eating very low carb for well over a decade. However, they will be the first to say that after a period of a few months at the start, they don't lose weight on them unless they are quite obese to start out.
The other thing that a very low carb diet will do for people with abnormal blood sugars--even those whose abnormality is well below the threshold that doctors use to define abnormal blood sugar--is eliminate the hunger that make it very tough to cut back on food intake.
But if cutting carbs doesn't make you feel better and eliminate rabid, compulsive hunger, there is no major advantage to eating that way. Because it really is all about the calories. But for many people with diabetes that rabid hunger is what is driving weight gain. No one who has not experienced diabetic-blood sugar-driven hunger can understand how it takes over your life and turns you into an eating machine. Still, after you eliminate the hunger, you have to eliminate the habit/social eating, which can also be tough. We are just so used to eating because it is time to eat, and because others are eating around us. Or because we are watching TV or at a party, etc.