According to premillenial view, What is the point of the Millenium reign? Here's my understanding:

Some people believe during the tribulation. They make into the 1000 year reign.

During this reign, there is peace on earth.

At the end of the 1000 years, Satan is released. Some of the descendants of the believers follow Satan.

There is a final battle.

Satan loses.

There is final judgment.

New Jerusalem arrives.

Now, what is the point of the 1000 year reign here? Is it to prove that Christ can do something that Satan could never do (i.e. real world peace?)
There are two main purposes to the millenial reign:

First, to show the world that the true problem isn't the devil (since he will locked away for 1000 years) but rather, the real problem is our evil hearts. Under the perfect and utopian rulership of Jesus, people will still choose to rebel and hate Him and wage war against Him.

Second, to prepare the earth for the coming of the Father. The Father doesn't come to earth until the end of the 1,000 years.