Why conjure the severe (or severest scenarios) to apply? None of us really can travel to a black hole, it is really more possible that a black hole would be traveling toward us. If so we could not escape. And from what is known with physics we could not survive that. Modern depictions of hell that I find from anyone are not what I would speak of as being reality. Fair judgment could be applied to all, of humans. Everyone would be without excuse for not looking, earlier people are included, There must be some from earlier times that we who would be saved will find have been saved too. The difference since the gospel of Christ has been revealed is that its message is available and being spread, for much more opportunity to all those reached to respond, along with all that is made known of Christ provided to them. Earlier individuals might have only responded for themselves without a message from them that would have others more likely to come to that than they already were. Abraham would have been pretty unique with effectively spreading faith of the one true God who should be trusted. A few others who were earlier were shown doing that too, still.
With fairness of justice in judgment from God it would be fairly applied to those apart from deliverance in Christ, who bore all of what is needed for any who come to him, that they are covered in him. As God he could bear all of that, which no mere human could do, so that deliverance is available. Conjuring the most extreme sentences imagined for others would not dispense the fairness in judgment that God can and will apply to any that remain apart from the deliverance provided. The fairness amounts to the different degrees any will suffer throughout the afterlife they come to, when there is the judgment for them, that will be with fair justice to them, for each.