The reboots are also canon
So after the Crisis, Earth 1 Steve was reborn as Nam veteran Steve with a new history and married Etta Candy, then after Flashpoint happened, he's reborn as a younger Steve and Etta is now black, both with new, different history, and then Doomsday Clock, Death Metal happened... same thing happened. They got a new history again, some of it the same, some new.