It’s important to know the difference between what we observe and what we imagine. We must do the same with the Bible. We must discern between the vision that the Holy Spirit is revealing through the Bible and what our imagination is adding to the Bible. The human mind is deceitful and desperately wicked beyond our ability to understand. Fortunately, the Holy Spirit provides this discernment. Being almighty, He has no trouble revealing the truth clearly to whoever will yield to Him. We need the Holy Spirit. We only run into trouble when we try to lean on our own ability to understand or when we’re drawn off the path by our own desires.
Nothing can be observed that tells us the age of the earth in any sense. The many indicators vary from a few thousand to billions of years, but they all depend on assumptions. Assumptions consist of made-up stuff. So they all depend on circular reasoning.
Though the Bible seems to indicate an age of a few thousand years, we can’t even declare the universal negative that billions of years didn’t happen. Though there’s no evidence for it, and nothing in Scripture suggests it, there could be something we don’t know. Of course, we also can’t say for certain that God didn’t make a planet inhabited by flying spaghetti monsters. Funny how people want to argue about the age of the earth but not about flying spaghetti monsters.