Your conclusion is correct but I would like to add some detail to augment your explanation.
Basically, every cell in your body needs some form of “SUGAR!” to survive as do cancer cells. “Blood sugar” or glucose is the primary source of energy for most of the cells in your body. When your blood sugar level drops below a certain level, your brain cells stop functioning, you lose consciousness, you stop breathing and you die. Sugars are not inherently bad, just as fats, proteins, oxygen, and water are not inherently bad. These are all ingredients that are necessary for us to live.
The problems caused by eating too many sweet foods are largely related to digestive and metabolic processes, and the way that your body reacts to eating sweet foods. And of course people's bodies often react far differently to various foods depending on a wide variety of factors. But in the United States especially people tend to eat vastly more sugar in their foods than what our bodies need.
Our consumption of sweet foods has “skyrocketed” in recent decades. “In 1822 Americans consumed an average of 45 grams of sugar every five days, or the amount of sugar in one can of coke.” “In 2012, Americans consumed an average of 756 grams of sugar every five days, that’s 130 pounds of sugar a year.” This is a huge change in diet and our bodies just do not handle this very well in many cases.
https://firstdescents.org/fd-healthy-sugar-how-it-affects-our-bodies/
Unfortunately, the explanations given in the link above are somewhat oversimplified and not completely accurate, but like your explanation they seem to come to the correct conclusion.
Missing in nearly all explanations of why sugary processed foods are not very healthy is this... processed foods simply do not contain a wide enough variety of nutrients to support a healthy gut flora. More and more studies have suggested in recent years that there is a very high correlation between a healthy gut flora and a strong and properly functioning immune system.
The proportion of sugar in candy and processed foods especially... is causing essential healthy bacteria in our intestines to die out and be replaced by bacteria that are less healthy and less diverse. This is most likely the primary reason eating less processed and less sugary foods increases your chances for good health.
Right... and one more thing to add is that there is a big time connection between prescription drugs and the damage that it does to the good microbes in one’s gut. At one time, it was believed that it was just the antibiotics that killed off the good gut bacteria....however, all the most recent research suggests that nearly 25% of prescription medication do the same thing from antipsychotics to antivirals.