In the interview below, Richard Dawkins is asked if he had a choice between death ( as "that's it") or heaven, which would he choose? He answers, "Give me two or three hundred years. But I think no longer than that. Eternity would be awful."
Dawkins is healthy, intelligent, and affluent. If two or three hundred years of that seems good, were it offered, why not a thousand, ten thousand, or more? What would make eternity awful?
Earlier in the interview, Dawkins was asked whether he would like it if there was a God. His answer : "What matters is what is true. The universe doesn't care what I like."
Eternity in an uncaring universe, apart from the God who is love, would indeed be awful.
It would be hell.