Q. What does Lord Krishna have to do with His lila (pastimes) with this samsar (material world), where almost everyone is envious of Krishna? Does the Lord have anything to enjoy in this material world or He simply comes to teach us out of His kindness?

A. The Lord is atmarama, fully self-satisfied  and always enjoying His own internal potency in the spiritual world.

He has nothing to enjoy in this material world  but He comes out of  His great compassion to not only teach us but by displaying His wonderful spiritual pastimes to attract the forgetful souls to the spiritual world and to His association.