Sure it can be. But a film version of MCU Avengers and MCU X-men would be an even bigger hit.
How so?
Personally prefer the prequel trilogy.
Again, how? Personally, it's as if HBO's Game of Thrones had swapped creative teams on their third season and gone so bad they decided to start prequel seasons with a new cast and they've been stuck on prequels ever since, when the fans know the source material goes on to greater things. Does that version of GoT sound like fun? Does it put this into perspective at all? It's also the fourth prequel installment. Usually, a trilogy stops at #3.
XMen had a lot of potential (much like Game of Thrones) to continue to be a great franchise. If only Singer had made XMen 3. Better yet, if only they had given Singer a chance at making an X4: Apocalypse like they had planned. Too many strikes, man.
And it's not a budget issue. (1) It was planned ahead of time. (2) They had Hugh Jackman and Jennifer Lawrence appear in Apocalypse.
(3) Characters come and go. Marvel's setting up Antman, Wasp, Captain Marvel, Black Panther, Dr. Strange, and Spiderman precisely because other longtime characters like Thor and Iron Man will eventually go out, and that brings down the cost of the cast. Where's Fox on that? They never gave us a proper Emma Frost, Gambit, Angel, a fully-developed Rogue and the list continues. (I still think Rogue and Cyke could've taken the lead) (4) You don't give Mystique the lead, for crying out loud. You wanted to correct an effed up timeline and lead to an even bigger mess? No! You should've killed Mystique and written Jennifer Lawrence out in Days of Future Past. That's what should've changed the timeline.
Also, Hugh Jackman was in 7 seven films in the role. That could have been at least five or six X-Men films and one or two spin offs.