Which is not a story Star Wars fans want to see especially since the books that have been out for 30 years have shown Luke's growth into the ultimate Jedi. He was an amazing Jedi master that brought the jedi order back from the brink of extinction.
He should be overmatched against Darth Vader and the Emperor, 2 of the most powerful force users in the universe. Even though he had hardcore training for several months with the greatest Jedi master, Yoda and his basic level training with Obiwan (also a top tier jedi), He shouldn't just show up and beat them with no effort. Unlike Rey Palpatine who can beat a trained force user after just picking up a lightsaber for the first time or defeating the emperor because she has a second lightsaber because more is better.
No one wants to see a story of the greatest hero in the Star Wars universe be a miserable failure. We got that with TLJ and it almost ended Star Wars.