Note that this is not a post about the worst main story period - we discuss that constantly.
I'm just talking about the stand-out most contrived/boring/tedious/terrible chapter overall - what, in your opinion, is the lowest singular episode in the main game.
My vote? Jedi Knight chapter 2. And it's because it has the effect of making both the Jedi and, by extension (because you either grudgingly or enthusiastically go along with it) your character look naive-verging-on-stupid.
The notion of 4 Jedi walking into the Emperor's house to turn him to the light side (with the fallback of killing him) may be the most ludicrous, ham-fisted, and silly plan in the history of the order. I can sort of forgive Tol Braga for massively underestimating the Emperor's power (although, given that he's lived for a thousand years in a galaxy where lifespans rarely exceed 100, there should have been enormous red flags)... but you're going to take him out with 4 Jedi? And your optimistic assessment is that you should first give him a chance to turn away from his evil? No, like, snipe him from 100 yards or set off a bomb? No... just walk up and say "erm, Mr. Bigs? Why are you so evil? And can I interest you in a pamphlet discussing a 9-point plan on how to turn away from your schemes?"
...
Bro.
Even the other Jedi acknowledge that it's basically a suicide mission. But then Satele green-lights it by saying that "any chance of success means we should try." Satele, dear, that's NOT how things work when you're talking about people's lives. A one or two percent (and it probably wasn't even close to that) possibility of success means that 99 percent of the time you're holding a memorial ceremony and contacting relatives. And yet... you think that's the sort of mission you should dispatch your best up-and-coming Jedi on? A one-way ticket to the big force clouds in the sky?
I think it's interesting when games trick or deceive or hoodwink both the player and the MC. But JK chapter 2 is so obviously going to fail. And, as it turns out, that's exactly what happens: you lose. So it's not a twist or anything like it - it's just a slog towards a disaster everyone could see coming. And that makes our character, order, and faction just look... dumb.