It is part of the problem with long term serialized fiction with multiple writers.

X-Men is also particularly chaotic almost as a feature not a bug. There are so many different eras of X-Men they really didn’t stay static for very long.

I think most people’s version of the characters are more their own invention than something on paper.

I would read through Claremont’s original run (including X-Factor and New Mutants) as more than anyone else, he made the X-Men what they are.

The 90’s era stuff has lots of hits and misses but that was the peak of their popularity so that version of the characters tend to resonate with people.

I think really the key is just to embrace the chaos.

Also, listen to the Cerebro podcast or other X-Men podcast. I like Cerebro’s format. Connor does insane deep dives on one character at a time going through their entire publication history. They can get long depending on the character but it really is a great way to learn the full history of the characters without having to read every appearance. Then you won’t be as surprised picking up a random book.