Kicking the XP would have meant the chiefs winning by 3 or 7.
The raiders had a better shot at winning this my missing the 2 point conversion than making the XP to tie it.
If they had made the 2, they might have gotten lucky with a TO, but still would have had time to win because the chiefs wouldn’t have dilly dallied getting to FG range, and you can better conserve time once the chiefs got into range