That’s how it played out in the leaked second draft of DotF, and tbh, I don’t like it. It feels weirdly disconnected having the lightsaber on a completely different planet. They move it to the same planet in the next draft iirc.
Regardless, the Battle of Exegol simply does not work without Rey and Ben being there. Them fighting Palpatine is the lynchpin of that entire scene.
yes i agree with that about DotF. While there were certainly some aspects in DotF that seems cooler than what we got. The whole finale battle thing seems a little odd. Kylo is on a complete independent vendetta and the their final duel is disconnected from the battle at hand.
The battle of exegol is essentially a re-run of ROTJ where its palpatine trying to goad said subject to strike him down to fulfill his objective. While there are elements that are different than ROTJ (dyad, palpatine actually restoring himself etc). At this piont, its a matter of taste on how different it is to ROTJ and if there are any creative/meaningful ways to make the rey, ben, palpatine interaction more “original/novel” but thats a different discussion. I personally like what we got in episode 9 for what it was worth