It’s great you took on this question, you present a lot to chew on. It seems the burden of proof should be on showing the question is not in vain. Kant talked about how we perceive the world in space and time. Wittgenstein talked about how language traces the limits of our thought. So when someone talks about eternity or infinity, these concepts are arguably not concepts at all. They are words to point to a negation, a nothing. Specifically, they seem to point to something outside of space and time, and so something outside our imagination – literally, in other words, unimaginable. How can it make sense to say “imagine something you cannot imagine?”

Heidegger asked “what is being?” a question closely related to “why is there something rather than nothing?” The absence of being, of something, seems similarly unimaginable. Arguably, Heidegger thought “what is being?” to be unanswerable, that we should keep asking the question, even though there is no what, that "being" just is.