Modern translations have lost the metaphor by translating הֶ֫בֶל as meaningless, but the Ecclesiastes isn't saying that life has no meaning; rather, that the meaning of life is never clear! Like smoke, life is confusing, disorienting, and uncontrollable. The book is by no means telling you that the things you do have no meaning or purpose, rather that you can never know with certainty where they're going to lead you. It's not saying that the reality of the world is that it's worthless, just that the worth is so perplexing and difficult to find and get a hold of; it's not that life actually is pointless, but that it's unpredictable and uncontrollable nature can leave you feeling like it's pointless. This is a fact of life that no one can argue with. This book is not an atheist's book; it's an every human on earth book. If you tell me that you've never felt like life is meaningless before, then I know you are lying, because every human who has ever lived has. That is the mere fact that the book is trying to convey. So, when you see "meaningless" in your translations, don't think that the book is telling you that life is, in reality, meaningless, because that would go against the rest of what the Bible says; rather, think that it's telling you that life is perplexing and unpredictable, such that at times it can leave you believing that there's no point to anything. This does not go against anything that the Bible says. It's recorded in the Bible that Elijah, a righteous prophet, had suicidal thoughts(1 Kings 19:4)! If that man did not thoroughly believe that life was pointless at that moment, then no one does! So, no, Ecclesiastes does not go againstoppose the Bible when it says that life, wisdom, or anything elseetc. is הֶ֫בֶל.
I hope this illustration showsstory illustrates to you just how utterly absurd it is to say that "there is no knowledge in Sheol" actually means "there is no knowledge about the earth and those living on it" simply because what came before the statement was about the earth and those living on it. The subject of what the author was saying changed(who knew that was possible?). At first, the subject was the living/life, then the subject was about the dead. Simple as that. If the author wanted to say "there is no knowledge about life/the living in Sheol", then the author could have easily said that. But he didn't. It's almost as if the author didn't want you to think that "there is no knowledge in Sheol" means "there is no knowledge about life and the earth in Sheol", and that's why he didn't say that. So I ask, stop adding to scripture what clearly isn't there. Paul warns us about that in 1 Corinthians 4:6.
