I want to understand all these viewpoints and see where y'all are coming from.
Well there are many reasons for why I don't believe but I'll provide a few:
1) The religion you follow is a consequence of your geographical location. I mean, have you ever wondered why the majority of Christians born in Christian countries tend to be Christian? Or how the majority of Muslims who are born in Muslim countries tend to be Muslims? The religion you hold will most likely depend on where you were born and what religion that place favours as the 'truth'.
2) Religion has justified some of humanities most absurd atrocities. You had the crusades, the inquisition and the justification of slavery by race in Christianity, but you also had explicit sanction of slavery, discrimination and massacres endorsed by Islam. Of course this is only a drop in the ocean. The prophet assassinated his critics, massacred entire tribes for the supposed actions of a few, married as many women as he liked whilst also having concubines, he endorsed sex slavery and many more atrocious things. To add to this, let's not forget about the explicit sexism in Islam. A woman who is raped is required to provide four male witness to prove she was raped by whom ever she accuses, her testimony is worth half that of a man, her inheritance is much lower than her brothers, the prophet explicitly stated that any nation led by women is bound to fail, she can be hit by her husband but not so hard as to leave a mark, her intelligence and religion is lower than that of a man and so on.
3) Islam portrays itself as a champion of monotheism but has established pagan rituals and practices within its teachings. The hajj, the tawaf, safa and marwa, salah, the symbolic throwing of stones at the devil, the veneration of a black stone and so on, are all fundamental aspects of the teachings of the religion but history shows that Islam didn't invent them, it took them from pagans. Some would argue that this was originally founded by Abraham and the pagans corrupted his religion, nonetheless, there is literally zero evidence for such claims whatsoever.
4) Scientific contradictions. Islam espouses a creationist outlook of the world, claims the earth was created before the heavens (universe), claims the stars are lamps meant to beautify the sky when that is clearly not true and so on. The Hadiths are even more ridiculous. It claims that the seasonal changes are a consequence of the inhaling of hell, meat rots because of the people of Israel and not due to decomposition triggered by bacteria, the resemblance of a child depends on who reaches the state of orgasm first and so on. Point is, it is clearly a book that contradicts the scientific evidence.
There's even more but I don't want to flood the place.