The ships that are destroyed in the planetary sequence are First Order ones.
Nah, doesn’t Palps tell Pryde to join up with the Sith Fleet? I took that to mean that they incorporated all of the First Order assets into the Sith Fleet and they all became one huge force.
Dude, are you telling me that the central conflict they had been building up for two and a half films (the First Order) was resolved off-screen by a bunch of unknown people whom we never meet? While our protagonists were dicking around with a random side mission?
God, I hate this film.
Why would they move all their assets directly on exegol? That just sounds illogical. It’s not so different that in RotJ, the entire imperial fleet was not all present at the battle of Endor. I don’t think it’s that hard to imagine that a sizeable portion of the first order fleet is regrouped on exegol while the remaining ships scattered across the galaxy remained in place.
So no, it’s not a side mission persay. While in TrOS there’s many things that are nonsensical, I just don’t see this as a reason and if at all, one of the major ones.