Why is pyruvic acid never the end product of fermentation

Pyruvic acid is not the end product of fermentation because in fermentation the pyruvic acid is converted into alcohol/lactic acid and carbon dioxide. There are two types of fermentation alcoholic fermentation and lactic acid fermentation.

In alcoholic fermentation, pyruvate is converted into ethanol and CO2 for example in yeast and in lactic acid fermentation pyruvate is converted into lactic acid and CO2 for example in animals muscles.

Therefore in fermentation pyruvic acid is not the end product of fermentation. In fermentation 2 ATP is produced.