In my opinion, Macbeth is a tragic hero. I see a tragic hero as a character who is admired and loved and followed throughout the play, and is bought down by a flaw in their character followed by fate. Macbeth is a brave hero, highly ranked by his own family and society, as well as the country. I see the reason for this, however, as the following: He is a brute. He is a violent, blood-loving butcher, and these are the activities, which got him to the status at which he is, a general...
any of these, only that the witches were responsible.

There are other examples also, that the Elizabethan audience would consider the witches responsible for, like Macbeth's lack of fear, disturbed behaviour, indifference to life and also invitation to evil spirits.

When focusing mainly on the supernatural details of the play, the witches seemed to me as the most powerful element of the play, otherwise, Macbeth seemed like a power-hungry mad murderer, but again, this is only my opinion. The Elizabethan audience would almost definitely consider the witches to be the most powerful element into the play.