Rev. 19:6, "…Alleluia! For the Lord God Omnipotent reigns!" Yes, our Father is omnipotent, all powerful, all seeing.
But, He is a Father, not a robot-builder. His creation was given the power of choice, along with all other powers and privileges attached to their level of being. Not only was man given the freedom to choose right and wrong,(Deuteronomy 30:19, "I call heaven and earth to record this day against you, that I have set before you life and cursing: therefore choose life, that both thou and thy seed may live.")but so were the angelic beings.
Ezekiel 28:15 tells us why Lucifer made his choice. "You were perfect in your ways from the day you were created, till iniquity was found in you." Vs. 17 "Your heart was lifted up because of your beauty. You corrupted your wisdom for the sake of you splendor." Isa. 14 elaborates on Lucifer's pride, verses 12-21, but I will only cite 12-14, "How you are fallen from Heaven O Lucifer, son of the morning! How you are cut down to the ground, You who weakened the nations! For you have said in your heart: I will ascend into heaven, I will exalt my throne above the stars of God; I will also sit on the mount of the congregation on the farthest sides of the north: I will ascend above the heights of the clouds, I will be like the Most High:"
We see the motivation, so why did God create him in the first place? Because Lucifer could have decided NOT made that choice. Lucifer was a beautiful and beloved child of the Father. When we have children, sometimes we can see ahead that they will make bad choices. As free moral agents, we cannot stop them, although we can make efforts to educated them along the way. Not until they have crossed an ultimate line, do we become estranged from them.
God could have created us all without the ability to choose our course. But then what would love mean? He wanted a universal family of loving, righteous beings and has provided a plan for its accomplishment.
Had Lucifer not sinned, there is no way to conclude that someone in the human or angelic races may not have made such a choice at some time.