Why does front diff stay locked in 2wd?

In many four-wheel-drive vehicles, the front differential can remain locked in 2WD mode due to the design of the drivetrain. This setup is often intended to improve traction on slippery surfaces, as it allows for better power distribution to the front wheels. However, if the front differential is locked, it can lead to increased tire wear and handling issues on dry pavement. To ensure proper operation and minimize wear, some systems allow for automatic unlocking of the front differential when not needed.