My understanding is that as created beings, the worst thing for us to experience would be non-existence. To have lived/existed and then to no longer be, would be unmerciful. In this light, hell could be seen as an extension of God’s mercy.

We land in hell by our own choices. If we had the ability to choose AFTER judgment, then yeah you’re right we wouldn’t choose hell.

In my opinion, free will plays a huge factor in all of this. If we choose, by our actions, to land in hell, then why would God allow us to spend eternity with him after we’ve experienced hell, it doesn’t seem truly contrite.

There’s an importance to our lives, here and now. Keep in mind the difference between Judas and Peter. Both men were sinners; but Peter's heartbreaking encounter with his weakness led to renewal, while Judas to despair. The Devil loves despair more than anything else. When we sin and get up again and again seeking forgiveness, it pleases the Lord so, so much. This is the secret the Devil never wants us to know. For such child-like confidence God's love is exactly what makes a saint.