The sugar itself in the fruit is not particularly better or worse for you than the sugar in sweets, but fruit is better for you than processed sweets. You’re eating the entire unit of food, not just one component of food. It depends on the fruit exactly how much but fruit will have fiber and many vitamins, but lack things like sodium or saturated fat. The fruit (as long as it’s fresh) also has no added sugar, and is usually also hydrating. A piece of chocolate cake has not too much in the way of vitamins or fiber (though it has a surprising amount of iron), but is full of added sugar and saturated fat.

Also, since you separated “chocolate” from desserts, I’m going to say that “chocolate” itself isn’t necessarily bad for you or so high in sugar that you shouldn’t eat it ever. (To be fair, desserts aren’t bad enough for you that you should never eat them either.)