Right. The key to success, the number one thing Marvel has to do for the X-Men -- is get people to care about the X-Men. Get people invested in them. Give them a stake in the story & then build on that investment in subsequent movies. This is how the MCU has thrived all of these years; that's why Endgame is such a huge deal. A whole generation of people have grown up with these characters -- it feels like they are saying goodbye to a family friend now. And that's the problem with all of the X-Men films, the actual X-Men are an afterthought. The audience never has a chance to connect with anybody because the wonderful relationships and character dynamics are constantly being squandered by writers and execs who don't understand the X-Men.
I firmly believe that with time, Marvel can make people love the X-Men as much as they love the Avengers. Like you said, I hope that 10-12 years from now, a huge X-Men event like Muir Island, Age of Apocalypse or Utopia, actually matters to people. And it's not just another run-of-the-mill Singer-Men movie