1) Completely Its Own Beast
As much as we enjoy the Marvel Cinematic Universe and (at least the potential of) the DC Extended Universe, there’s a valid point to be made that their movies are more like feature-length television episodes, as their stories can never really end considering that their franchise has to keep going forwards. The X-Men franchise doesn’t suffer from this to the same extent but, lately, the strain of all the variant continuities of the series has weighed down on the movies.
Logan does away with that problem entirely by cutting its ties completely with the wider X-Men franchise. The cast and crew have spoken in the media about how it takes place in a slightly alternate universe from previous movies, but the film itself isn’t interested in clarifying anything so nerdy. It just wants to tell its own story and be done with it.
Would we have loved to have some flashback to the X-Mansion with, say, Famke Jansen and James Marsden? Sure, but, if we set aside our fanboy cravings, the decision to leave Logan as its own beast was definitely the right one for the movie’s integrity.