Okay so Lucifer obviously upset his sky-daddy, is demoted from being an angel permanently, is cast down to rule an entire sector of the afterlife called Hell which we come to know where all damned souls go after they die.
What is the logic of God practically awarding Lucifer an entire realm for him to rule on his own and nearly contest God’s power?
That’s like imprisoning someone to home confinement when they live in a mansion.
Modern Christian mythology is a mashup of a lot of things. A scholar would be required to really unpack a lot of it, but consider that much of what we think of as lore, motivation, and character are newer additions. Dante’s Inferno probably has more influence on our ideas about Lucifer and Hell than the Bible.
Once you start unpacking these old stories with a post-modern mindset, the logic of it quickly stops making sense.
A modern Christian might opine that Lucifer is a prisoner of Hell but not a genuine threat to the power of their Almighty God. He’s not awarded this position. He’s lost God’s grace and dwells outside of his love - the worst punishment imaginable in the mind of some Christians.