Like Qui-Gon? Or Darth Maul? Or Count Dooku? Or Obi-Wan? Or… pretty much ever character that we have ever watched get killed by a lightsaber? In fact, the only character I can think of ( and I am sure I might be wrong) who takes more than one blow from a Saber and comes out of it with fight left in him is Darth Vader.
It seems that the definition of lightsaber combat is that the people involved are incredibly skilled, and it only takes one blow to kill. I for one would embrace that style with all my heart, as it would allow for really cool and epic lightsaber duels.
I suspect that once you try it you will see the downsides. :0)
DnD/Saga style inflatable hit points can be seen as representing this kind of fight. Attacks are not doing damage, but wearing down an opponent until the final strike that takes them out of the game.
And this has its advantages. It is more predictable - if rather than a 1/10 chance of killing someone outright, you take 10% of their hit points off, you can guarantee the fight will last ten rounds, where as with 1/10 chance of an instakill, they may be ganked on the first round, or you can keep missing the roll for ages.
Perhaps more important, you can see how they are going. If your hit points are depleting faster than your opponents, you can see you will lose and do something about it by running away or whatever. But if after an instakill round you are both still alive, well, it is exactly the same as it was before the round so you have no better idea of who is likely to win eventually.
Plus it really sucks to have a much loved character cut in half because you rolled a one on the first dice of a combat.
Now, I guess resources like fate points or whatever you can use to get you out of an instakill can mitigate this, but at that point the fate points ARE your hit points - the fight is over when you run out of fate points, same as if you run out of HP.
Or, in short, I frigging hate GURPS these days after years of trying to use it for entirely the wrong sort of games. Like, for instance, Star Wars. :-)
Personally I am still waiting for TTRPGs to catch up with the current thinking in video games and have 'health' regenerate if you hide behind cover for a few seconds.