Why is cow meat called beef, pig meat called pork, but chicken meat just called chicken?

"According do Reddit User Teekno, this practice dates back to the Norman Invasion of Britain:

“For centuries afterwards, the nobility spoke French, and the peasants spoke English. So we have French-derived words for the meat (because the nobility enjoyed the meat) and English-derived words for the animals (because the peasants were the ones that had to raise them).

Chicken was not a “fancy” food at the time and typically didn’t end up on the nobility’s table. The big roaster chickens of today didn’t really exist yet, so there wasn’t a lot of meat available from it. So when the were slaughtered for food, they often went into stews eaten by the farmers.

That’s why we really don’t have a separate word in English that means “the meat of a chicken.”"