Giving Reasons. (I’ve received several questions on this topic.)
What’s the difference between because, on account of, owing to the fact that, as, on account of, due to, and since? There are a lot of words here and the answer is: Not much difference. Of course no serious writer ever uses because the reason is or the reason why. Both are redundant.
Purists can (and do) distinguish, but most of us see it as a matter of personal taste. I've noticed that writers who want to sound scholarly tend to use due to most of the time. I suppose it sounds more intellectual. I associate it with the writers of the past two centuries.
The rule is that due to modifies nouns and follows state-of-being verbs (am, is, were). In reality, due to has become a generally accepted synonym for because.
Since refers to time, according to the purists, but most people either ignore that or aren't aware. Today, since and because can be synonyms. The same is true for using as when you mean because.
In short, English offers many ways to express reasons and the distinction has long been lost, except to people who love to cite rules.