There are probably more ways to answer that question than we might think.

Privacy is the first thing that comes to my mind. Non-KYC helps improve my ability to transact with others in a private way. Just like we are able to go to a shop and spend physical cash with only myself and the shopkeeper knowing the transaction details, non-KYC allows me to do the same, as their is no link between my ID and the cash/sats I've spent. (This is why the title reads Bitcoin: A Peer-to-Peer Electronic Cash System)

People who may provide more substance than I include #[4] and #[5]

Hope this helps .. 🤙🏼