Hi Zoli, you are definitely correct, the Bible was never meant to be a science textbook. That said, there are many reasons why taking the Bible literally is important.
Perhaps first and foremost is this, if the Creation is considered to be nothing more than a "real nice story", but not true, why should we believe that any of the other "stories" God tells us in the Bible are true? The other question is, if you choose to believe that "some" of the stories in the Bible are true and others aren't (especially when the various stories we are considering are written in an equally believable manner), how do we determine which story is true and which one isn't
There is also the matter of "assignments", which is particularly important when we are trying to decide who to "assign" the title of "
Author of Evil" to. Because our sin is a universal trait among our race, we know that it has to have a single cause, and if our progenitors are not the cause (as the Bible tells us they are), that means that God must be

IOW, if our race doesn't have "first parents" as the proximate cause of our fallen nature, then the way we are now (IOW,
by nature, children of wrath ..
Ephesians 2:3) is the way God made us!
These are but two of the reasons (and I hope that makes sense to you).
Yours in Christ,
David