Jokes aside, there are a few natural sugar sources without fiber, like sugar cane (it has fiber, but we just spit it). I think we can all agree that eating too much honey or sugar cane juice would be bad for our health.
There's also sugars like inulin (https://en.wikipedia.org/wiki/Inulin), which are actually classified as soluble fiber because we can't digest them, so the bacteria in our digestive system does it for us. Inulin is a prebiotic, so it's actually healthy to eat in moderation.
Inulins just aren't sugars. As you say, they're categorized as soluble fiber. Any definition of sugar that included inulins would include all soluble fibers.
Jokes aside, there are a few natural sugar sources without fiber, like sugar cane (it has fiber, but we just spit it). I think we can all agree that eating too much honey or sugar cane juice would be bad for our health.
There's also sugars like inulin (https://en.wikipedia.org/wiki/Inulin), which are actually classified as soluble fiber because we can't digest them, so the bacteria in our digestive system does it for us. Inulin is a prebiotic, so it's actually healthy to eat in moderation.