My dear @Alski the version of English Americans speak is older than what the British, and Commonwealth nations do. In fact, brits didn't start calling cookies biscuits until the 1700s
The British use of "biscuit" for what Americans call a cookie solidified over time, especially with the rise of tea culture in the 1660s and the Industrial Revolution in the 1700s, when sweetened biscuits became a staple for workers. By the 19th century, the term was firmly established in British English to describe a wide range of crisp, sweet or savory baked goods.