Dark Phoenix highlights a problem with X-Men: The Last Stand
The X-Men never get to fight Phoenix.
The only confrontation they have with her is Xavier getting obliterated and Jean letting Logan stab her to death with little resistance. What makes it worse is how X2 builds up Jean just to have the following film do little to nothing with her.
It’s like Infinity War having Thanos never fight the Avengers or the Guardians instead just have him snap half the universe away. Then in Endgame he lets himself get defeated without much resistance after teasing at him so much.