If we put things in terms of “ceasing”, I recall the words of a bhikkhu some time back that stuck with me: “Only dukkha arises and only dukkha ceases”. From that, I take nibbana to be the complete cessation of dukkha, and nothing more.
Questions such has “Why haven’t I attained nibbana in this infinite samsara?” or “Why isn’t everything parinibbana?” have driven some people to an intellectual maze, and I’ve seen that too. There is a thread somewhere about how bizarre infinity can be. The only thing we can do is to appreciate the opportunity to be in a Buddha Sasana and the urgency to attain nibbana.
Hope this helps.
