Subsequent His atonement for sin and resurrection, why didn’t Jesus remain on Earth and rule? Why allow this present chaos?

There is an eschatological plan in-play; that plan was announced in Genesis 3:15 and the battle strategy for victory declared in Genesis 3:21. Jesus tells you that His Kingdom is NOT of this World and His servants that fight for Him are of a different Realm than this temporary Realm of Time and physics.

Jesus has been granted complete dominance over Time and Eternity (John 3:35) and He IS in complete control but the purposes for the creation of Time are playing-out according a specific eschatological strategy and what might seem like chaos in the World to you is actually a battle strategy that will stymie rebellion in the New Jerusalem, an eternal Kingdom replete with “free will” to manifest subsequent the destruction of Time, Earth, this temporary Universe.