Depends.....if you're the one selling coca cola or the one trying to lose weight. There's deffinately something about the artificial sweeteners though. I have seen studies where people only switch going from regular soda (FULL OF SUGAR) to diet sodas....and it ends up making less of a diff on weight loss then one would guess. Though it's a huge improvement on Blood Sugar obviously, and for liver health etc (sugar being poison).
My theory which is purely anecdotal, and experiance biased..is it has to do with appetite. Artifical Sweeteners are actually sweeter than sugar. And they push appetite in a big way so you eat/snack more, and it's harder to feel satisfied. (kinda like dieting while smoking the herb) So if you just drank water you would eat less then when you say drink artifical sweetened drink mix, or diet soda. Beyond that I am not sure....But they do seem to hamper weight loss. They also of course will continue to fake out your brain on when you need insulin, and therefore increase insulin resistance as your body tries to counter the false signal. I have also heard it can mess up your gut biome and health, but I have not taken the time too look into that. Heaven help me though they are harder to give up for me then nicotine. But If I could get past using them and stick to water and tea with no sweetener, I bet I would have lost twice as much. People doing just water butter bacon and beef are doing better faster. So while I may not succeed in eliminating them, I am trying to reduce them.