macOS is designed to put your Mac to sleep when it is not being used. That is usually exactly what you want. Sleep saves power, protects battery life, and keeps a MacBook from running when it is closed and stuffed in a bag.
Source: [9to5Mac](https://9to5mac.com/2026/06/12/how-to-keep-your-mac-awake-even-when-your-macbook-lid-is-closed/)