If hyperspace is a fifth dimension, why would Han to worry about flying into a star are too close to a supernova?
This is why official canon is dumb. Just go by what you see on the screen.
What is wrong with official canon if it maintains consistency and therefore believability throughout all movies referencing that canon? Not maintaining consistency on the other hand is actually dumb as it creates issues with the logic people have previously built around how such things work by what they were shown in previous movies.
Just going by what you see on screen is one of the many issues with TLJ, as it just expects you to go along with whatever it serves up with little to inadequate or no explanation as to why this is now allowed or works in this new way. For people who’s brains “checkout” when they sit down to a movie and just blindly accept whatever the movie shows them, this probably works though I’m sure many will process and think about things afterwards and suddenly think “hey, that doesn’t make sense!”.
But if your mind is actively processing what the movie is showing you in regards to your current knowledge and memory on such things, it is constantly going “um, what? how does that make any sense!?” and can be very distracting or even jarring when trying to watch the movie, aside from the fact that it detracts from it’s overall enjoyment. If this happens to core elements of a movie’s story, characters or canon then it can downright ruin the movie.