I think there’s always been a pretty serious disconnect in Star Wars between how the Jedi (and even Palpatine, actually) talk about the Dark Side and what we actually see of people who succumb to it.
The first we ever hear of the Dark Side is Obi-Wan’s initial description of Vader to Luke in ANH: “Vader was seduced by the Dark Side of the Force.” We don’t really get any more information in ANH itself, but the word “seduced” carries with it a lot of connotations: it makes it sound like the Dark Side is something tempting, something appealing, but also something that’s ultimately duplicitous.
And all of that is borne out by Yoda’s much more detailed explanation in ESB. The Dark Side, Yoda tells Luke, is quicker, easier, more seductive than the Light. And it’s fueled (or possibly produced? – actually he’s not really clear on this point) by anger, fear, and aggression.
If you put those two definitions together, the logical conclusion would be that the Dark Side gives people faster and easier access to power through these supposedly negative emotions, and that it’s very tempting to use the Dark Side because you can cut corners by doing so. It’s just as logical to conclude that Anakin must have fallen because he gave into that temptation to let the ends justify the means. And a lot of people seem to be assuming that something similar happened with Kylo Ren in TFA, as well.
Only that’s not actually what happened with Anakin at all.
Anakin doesn’t turn to the Dark Side because he thinks it’s easier. He turns because he’s desperate and he doesn’t think he has any other choice.
And he’s not really tempted by it, either. Not in any way that resembles the usual definition of temptation, anyway.
The closest Anakin comes to acting on temptation is actually in AOTC, when he slaughters the Tusken camp in rage and grief. That moment actually does line up with what Yoda tells Luke about the Dark Side.
But that moment doesn’t mark Anakin’s turn. It’s a step, yes, and it’s certainly a morally wrong action, but it’s entirely possible that something could have gone differently in ROTS and Anakin never would have turned at all. The really astonishing thing about ROTS is how close Anakin came to not falling at all.
And when he does turn, when he pledges himself to Palpatine knowing full well what he’s getting into, it’s in a moment that’s the exact opposite of anything that could be called quick, easy, or seductive. It’s certainly not a moment of power for him. He’s literally kneeling on the ground, selling himself to a Master, and Palpatine takes everything from him, even his name. (There is a reason I refer to Vader as his slave-name, okay.)
Anakin doesn’t give himself to Palpatine because it’s quicker or easier. He gives himself to Palpatine because he’s in a place of absolute despair, because as far as he can see he’s tried literally everything else, because in his mind this is his last option.
And it’s not an accident that he thinks so, either. Palpatine doesn’t convince Anakin to turn to the Dark Side in an instant. No, he’s put fifteen years of emotional manipulation and gaslighting and conditioning into this. He took a boy who was already vulnerable and traumatized and alienated from the people around him and he very carefully shaped that and poked and prodded at all the fractures until Anakin Skywalker was ready to break. Then Palpatine just had to make sure Anakin broke in exactly the way he wanted him to.
That’s not seduction. That’s conditioning. That’s the pattern of an abuser.
Anakin’s is the only “fall” we actually see happen in the movies (so far, at least – I suspect we’ll get some more flashbacks of Kylo’s eventually). But we can test Yoda’s theory but looking at a couple of near-brushes with the Dark Side in characters who don’t actually turn.
First, there’s Obi-Wan. Yes, really. In TPM, his reaction to Qui-Gon’s death is, understandably, one of horror quickly followed by absolute rage. I don’t think there can be any question that he attacks Darth Maul in anger, that he’s fighting for revenge and he’s fighting to kill.
By Yoda’s definition, we should be able to say that Obi-Wan was drawing on the Dark Side in that moment. But the narrative makes no moral judgement of him, and I don’t think he was ever in any danger of falling. He was just having a very understandable emotional reaction.
Probably the most telling example, though, is Luke. In ROTJ he steadfastly refuses to fight his father – until Anakin goads him by threatening Leia. And Luke loses it.
Why does he lose it? He’s angry, obviously, but I think it’s more than that. Luke in that moment is desperate. Things haven’t gone at all as he’d hoped. He wanted to save his father, but that’s not working out too well right now, and in spite of Yoda’s warning he did underestimate the powers of the Emperor and on top of that the Death Star is fully functional and it looks very likely that he and all of his friends are going to die here and there’s nothing he can do about it.
And now Vader is threatening Leia, too. Luke has nothing left.
When he attacks his father, he does so in a rage born of despair.
And what stops him from killing Anakin? What brings him back to himself?
It’s not Anakin, sprawled out wheezing and beaten on the floor. It’s not Luke’s better nature reasserting itself through the haze of despair.
Palpatine, offering him the chance to kill his father and take his place. Making, in fact, a seductive offer of power.
Which is exactly what Luke doesn’t want. And that realization is enough to break him free of his despair, to let him really see Anakin, and himself. And free of that despair, he finally finds the peace to free himself completely, and to show his father how to be free, too.
When Anakin turns back he does so because he loves his son, and because Luke has shown him the truth about himself. Because Luke has made him believe, for the first time in twenty years, that he can do something. That he has a real choice. That he has agency.
Is the Dark Side stronger? No, says Yoda.
But is it actually quicker, easier, more seductive? From everything we actually see, it’s not that either.
There is one thing that both Anakin and Ben say, in their most honest moments, and it has nothing to do with power or cutting corners or the ends justifying the means.
They both say, “It’s too late for me.”
So I submit to you that the Dark Side is, in fact, a reduction of agency, an absence (or at least a perceived absence) of choice, a constraining, binding force. Even more than anger, fear, or aggression, the Dark Side is defined by despair.