Ren

Well, Nick Gillard (Star Wars stunt coordinator) described lightsaber duels as "A game of chess, played at a thousand miles an hour", and that essentially answers everything.

In a game of chess, nobody is relying on time-based "reflexes" at all, and many individual moves are made with knowledge of how they can/will be countered. Despite this, someone eventually wins, because they backed the opponent into a corner they can't get out of. "Checkmate".

Lightsaber practitioners are engaging in drawn-out duels, wherein they both aim for that "Checkmate" via the long game. If this kind of combat could exist in real life, it would get very complicated, and would be filled with moves that have no practical way (or reason to) exist otherwise, because they would defy conventional swordplay logic.

Keep in mind also that the precognition a force user has is not concrete. It surely varies by user, by complexity, and by moment. Problematic mental states like fatigue or overconfidence could surely cloud one's vision and ability to predict, too. This mechanic of the combat is both a game changer and very very loose to observe.

Element 2: The blade itself is extremely weird, guys

The extent to which a lightsaber blade is nothing like a sword blade cannot by overstated.

People do try to quantify this difference with concepts like "The blade is weightless!" or "It can cut in any direction!" or "It cuts things using heat!", but funny enough... these things are never explicitly stated by the lore, nor are they well supported by what we see.

For one thing, it has been canonized that the "weight" of the blade is affected by the user's "connection" to it. This may be inspired by how a real sword's weight is easier to manipulate with good technique, but it goes a step further here, with mystical attunement that actually changes the properties of the blade. It might not be physical weight, but somehow the blade can resist the user, and it varies.

Kanan Jarrus also tells us that saber blades are somewhat "pulled towards each other", almost magnetically sticking together. This might explain something about why characters are always locking their blades together in combat, and tells us it could be effortful to pull one blade away from another (depending on the user?). Again, very magic-y, and nothing like a sword.

On that note, it has never been confirmed exactly how a lightsaber manages to slice through things. Yes, it seems to heat up objects it cuts through, but does that really mean it cuts with heat transfer alone? To whip through metal like butter, the blade would have to be about 20,000°C, or roughly four times hotter than the sun. Are we serious?

I do get the impression a lightsaber blade is quite hot, but considering the blade's weight is also canonically "magical" and flexible, its ability to cut things might also be influenced by user-based "magic". Is the blade really an omni-directional heat wand, or is its "edge" and capacity to cut partially a mystical thing? Hard to say.

Considering the fact that broad analysis of official Star Wars media does not support much consistency in the properties of blade, it makes sense to infer there's some "magic" happening, and that we'll never be able to fully quantify it. The force itself is soft magic as is, with its grounding logic being character driven, devoid of "RPG mechanic" clarity.

I think it's time to accept that a lightsaber blade is not only different from a sword, but also lacking in concrete nerd rules. What a character achieves with a lightsaber mostly tells us something about them, not the properties of their magic item.

It becomes very hard to decipher why a practitioner would perform a given maneuver when the blade behavior is such an unknown. Maybe spinning is a good trick. Hard to say.

Element 3: Fights in movies/cartoons are fakey fake

This is such a huge topic, it could be a whole book, but let's just summarize: Even when depicting real world combat styles, there are limitations and demands for making a great fight scene that don't always gel with utmost realism.

Once you combine the challenges of fake story-driven fight scenes with the fact that lightsaber combat is intrinsically fictional already (with impossible mechanics and unclear rules), depicting a "lightsaber fight" really does become an exercise in artistic interpretation.

Aside from the fact that the actors generally aren't real world martial artists (which can only help at best), and the props can never act like "real lightsabers" in every way, there's also just no way to design a scene that perfectly rationalizes what mastery of something so fictional would look like. Even in Star Wars animation, you're still just approximating, and can't stray too far from the visuals of the live action stuff.

You have to recognize that lightsaber fights are always intrinsically lacking absolute logic we can break down, and any given scene is an attempt at showing an idea of what it could look like for those characters.

This should be freeing and exciting to the viewer, rather than frustrating.

I used to dislike the "Seven forms of lightsaber combat" from the lore, due to their lack of concrete rules... but I later came to appreciate them for the same reason. By restricting the lore to a few vague ideas, you open the door to artistic interpretation, and shut out the pitfalls of "hard magic" that Star Wars isn't designed to accommodate.

Conclusion...

At the end of the day, this is space wizards with glowing magic swords. It's made up, it looks cool, and it serves the story. I'm all for analyzing it and caring about the choreography & lore, but it's also just so artificial. Critiquing it with too much attempted logic and authority is often paradoxically weaker than a lighter and more curious assessment. Ultimately, these scenes imaginatively interpret the lore and combat elements that are made clear to us, and that's the fun part.