Why do you think so many animal species have been named when most living on earth are monerans?

Your assumption is not correct. Monera is one of the early classifications of early life on Earth. Most living organisms on Earth are not monerans. In fact, monerans are a relatively small group of organisms compared to other groups, such as animals, plants, and fungi. Additionally, the number of named animal species is not necessarily related to the abundance or diversity of monerans. Animal species have been extensively studied and classified for various reasons, including scientific research, conservation efforts, and human curiosity.