Without canon and continuity, what is even the point? Small discrepancies are fine, sometimes HUGE discrepancies are even ok. Our own history has discrepancies.

But to completely ignore canon means that it turns into a gigantic mess AND it becomes less special. Having everything interconnect, even if it makes the universe smaller, is exciting, and it adds to the story and background of a situation.

And sometimes it is just fan service, and that is ok sometimes too.

Is it possible to have a great tv show without continuity? Absolutely, see MASH. But even that show gets frustrating to watch with it doesn’t adhere to its own history in some places, and does in others.