That’s a debatable point.
Sugar is typically sucrose, which is a glucose and fructose combo molecule. Both substrates are broken down in your body differently, so they are not metabolically equal. To put it simply, glucose ends up in your blood, and fructose is processed by your liver, making triglycerides, and which can lead to problems if too much is ingested (ie fatty liver disease).
Starches, on the other hand, are glucose molecules attached, as long chains. So, when broken down, they (the glucose parts) follow the same metabolic process as the glucose part of the sucrose (glucose + fructose) molecule.
To me…it’s all sugar. I don’t care if corn starch and wheat flour isn’t sweet when you taste it. My body doesn’t give a crap if the glucose came from flour or an apple. It’s all the same. To other people, they consider sugar and starches as separate.