Discounting such falacies as "Is God powerful enough to create a rock that He cannot move?", YES.
Yet, you fail to answer my simple question to you: Why is it that God does not exercise His power to ensure the salvation of all?
(It appears that we are in agreement concerning His power, maybe you can begin to contemplate His purposes.)
You misstate your question in that I am not a universalist.
A correct question would be: "Why is it that God does not exercise His power to make possible the salvation of all?"
The answer is that God IS POWERFUL ENOUGH to make POSSIBLE the salvation of all!"