Are the women in Macbeth are directly responsible for causing Macbeth’s downfall?

One school of thought would argue that we are responsible for our own actions. Thus, if we take an existentialist view, Macbeth directly makes his choices and suffers the consequences of them. The witches only tell him their prophecies; they do not force him to commit murder. Lady Macbeth, for all her belittling and emasculating comments, does not guide Macbeth's hand to his heinous act. It seems Macbeth is quite easily convinced by her insults to his manhood: "When you durst do it, then you were a man." Although the witches do plant the thought in Macbeth's mind, and Lady Macbeth goads him, none of these characters can force Macbeth to do anything that isn't already in his mind. After his first murder, Macbeth becomes much more callous and commits more wicked deeds, keeping Lady Macbeth in the dark about his decisions. He is willing to kill his best friend Banquo and his son Fleance, as well as the innocent Macduff family. Even though he sends murderers to do his dirty work, Macbeth has made the decisions and sets the forces in motion. No one is advising him at this point because he trusts no one. Additionally, he becomes quite overconfident and arrogant, which causes him to make mistakes, such as underestimating Macduff's power or assuming that "none of woman born" can kill him. Therefore, Macbeth is directly responsible for his own downfall. The key word in this question is "directly." We might argue that the women are indirect contributors, but Macbeth must be held accountable for his own actions.

In my view, the answer is no. Macbeth already has within himself the seeds of his own destruction when the play opens.
Perhaps the importance of Macbeth's fearful reaction, observed by Banquo, to the witches' prophecy has been overstated. This, however, is the key to the whole plot. Macbeth has probably already had the notion of doing something out of bounds in order to "overstep" his current status and eventually take over the kingdom. The prophecy of the witches is stated ambiguously: in no way do they order Macbeth to commit murder, nor do they indicate exactly how his elevation is to occur.
The question of Lady Macbeth's influence is, perhaps, more complex, but the point is the same. There's no doubt that her urgings play a role in his criminal behavior. But she nowhere makes any explicit demand or threat if he refuses to follow her advice. After stating (as if with finality) that "we will proceed no further in this business," he changes his mind in about one minute and decides to go through with the killing. Macbeth is a man possessed, by his inner demons or by some mystical, irrational power that drives him on against his own judgment. This is precisely why the tragedy is so moving. If Macbeth were merely a sociopath, not knowing right from wrong, or if, on the other hand, he were a helpless man manipulated by his wife's threats or by some hypnotic power she or the witches had over him, we would not identify with him and his plight. He is an anti-hero, a quasi-villain with whom we identify because the destructive urge is part of his inner self—in other words, part of humanity as a whole.