There are many claims that the bible is a supreme text. Without a doubt, it is a very significant text in history and in the lives of many believers.
However, the claim isn't that it's merely special. The claim is that it is divine. So, what would we expect from a book which has the explicit purpose of educating mankind about the nature and desires of a God? A short list might be:
1 - Unambiguously super-intelligent 2 - Morally clear and unchanging 3 - Absolutely no contradictions and contextually/socially portable 4 - Not anthropomoprphic 5 - Unique in its tone and tenor as compared to all other spiritual texts
Unfortunately the bible fails all of these tests.
When it makes testable claims, it either does so around immediately obvious information or gets it wrong (Genesis is rife with straightforwardly false information about the world). At no point does the bible make any claim about the universe as we know it now that reflects any impossible (or even significant) insight regarding the natural world. It is possible that God just isn't concerned about human suffering - or at least not enough to recommend even the slightest hint at what could have alleviated eons of pain via basic sanitary information.
When recommending moral law, it only ever does so within the confines and norms of the time of writing. There is nothing revolutionary or abnormal in the old testament with regard to moral norms. Stoning is ok. Slavery is ok. Genocide is ok (and promoted). Aliens observing the warring tribes would likely not notice one tribe adhering to the old testament as substantially different in its behavior/motives than those not adhering to it. The new testament truncated some Jewish rituals and inspired some to self sacrifice (although it also inspired eons of infighting and brutal torture as well).
The bible is chock-full of contradictions. Armies of apologists are on hand to resolve them via a myriad of ad-hoc theories and assumptions around norms of the day, alternate interpretations, “original language” meanings while missing the original transcripts, etc… and they fight with each other too. At the end of the day, a plain reading in the vernacular shows the bible to be absolutely teaming with contradictions. If language/translation induced, why let the original languages die? If not, why allow inferior translations? An omnipotent author could have easily avoided this problem
The descriptions of God in the bible begin as a raging, jealous war god. It develops over time toward a very angry, but patient and distant father figure, still ready to kick your ass up and down the street. The current instance is a personal, loving being much like a really good therapist. None of Gods described motives or behaviors are very remarkable when viewed through a human lens. They are, however, stunted, petty, violent, and shocking when viewed through what one would hope to find in the mind of a being capable of inventing man.
Finally, the bible isn't remarkable enough to dissuade those born to other sects in other places to regard it as superior to their texts. When, after long last, one views the bible without assuming what one was told from childhood about it - it really does shrink to the scale of other mythological texts carried forward from ancient times.