I’ve yet to see a compelling argument from the original languages where the descriptor for the fate of the unbeliever is eternal. I only see the descriptor applied to the torment tool itself being so, which makes sense as it was designed for eternal beings - fallen angels and the like. Also, plenty of scriptures about impurities being “burned away.” So, it’s my view that the fires are eternal, and the suffering is eternal for the eternal beings, but eventually the torment of the unbelievers ends as they are burned away.