Except most blueberries arent actually blueberries. They're normally a mix of; sugar, corn syrup, starch, hydrogenated oil, artificial flavors and artificial food dye blue No. 2 and red No. 40.  Particularly by cereal manufacturers including Kellogs, General Mills...

https://www.latimes.com/health/la-xpm-2011-jan-20-la-heb-fake-blueberries-20110120-story.html

https://www.npr.org/sections/health-shots/2011/01/20/133089144/fake-blueberries-often-masquerade-as-real-fruit#:~:text=Instead%20of%20using%20real%20blueberries,with%20packaged%20cereal%20claims%20before.