Between 1963-1992 I can count the number of days, in total, Charles and Magneto met up.
They knew each other and hung out for a few days in First Class, and then no contact for 10 years between FC and its sequel. Then Xavier helps Magneto escape his Pentagon cell in DOFP and after an over night flight to Paris together, Magneto tries to kill Mystique the next day, after which they then meet again in DC where Magneto tries to kill Nixon and his cabinet the following day. No contact between the "good friends" until Magneto shows up at the mansion with Apocalypse a decade later, spending a day max together in Egypt with a kidnapped Xavier, Erik helps to bring about the literal apocalypse, only to do his umteenth heel turn and is then name-dropped by news organizations as the primary hero in 1983 (Mystique was the one who saved the world in 1973) with no mention of the X-men.
Kinberg would have us believe the X-men are now national heroes in Dark Phoenix.
Kinberg would also have us believe that Magneto has been doing nothing but good deeds since the end of Apocalypse, and is in turn saving soldiers when other mutants are doing them harm. Yes that Magneto...
I would advocate for Kinberg to write a joke in about how Charles and Magneto have only met once every ten years but it would be a Kinberg-written joke. No one wants that.
I've said it once, I've said it a thousand times, these decade hopping shenanigans is the very definition of laziness. Singer and Kinberg love the decade jumping because it covers their tracks when it comes to this franchise's less-than-stellar continuity record.