The friction between the two surfaces is because of the interlocking of the irregularities of the two surfaces. ... But, when the object is at rest, the surfaces interlock well, therefore friction is more. This explains why sliding friction is less than static friction.

Why is static friction higher?

Static friction is greater than kinetic friction because there are more forces at work keeping an object stationary than there are forces working to resist an object once it is in motion.

Why is sliding friction less than static friction short answer?

The sliding friction is less than static friction because of the interlocking of irregularities in the two surfaces. When the object starts sliding the contact points on its surface, do not get enough time to lock into the contact points on the floor. So the sliding friction is slightly less than the static friction.