DC didn’t invent continuity. DC’s readers invented continuity and inflicted it upon the editors, who loathed it and resisted it and ridiculed it every step of the way. DC has always preferred to tell the same story every month and they’d love it if we let them…but we didn’t, and in the 1960s and 70s capitalism actually worked for once and the authors who could create continuity sold so well that they couldn’t ignore it.
Now it has trapped them. They thought that, with reboots, they could essentially repackage and resell the same general package of stories over and over again, like the record companies sold us all the LPs, the tapes, and then the CDs. But it’s not working because the past won’t stay dead — continuity doesn’t work that way. The old stories still exist in the mythic space of our memories, and by introducing the in-universe mechanism of energy-based reboots they’ve ensured that the old methods of dealing with continuity problems (quietly and politely ignoring them, “surprising revelations,” “it was all a dream,” etc.) don’t work any more. All DC history exists at the same time — everything happened, nothing happened. In the DC multiverse there is a world where it’s still the Golden Age Superman, and no crisis however hysterical can dislodge it.