Btw a thriving canadian comics industry would not automatically keep John Byrne from doing the Superman reboot of 1986. And even if it did, how do we know that we would not have gotten an even worse reboot instead?
But we can always dream. I'm sure in one universe at least it happened. Maybe in that universe the Crisis didn't happen. I don't know what I'd prefer: Byrne remaining a Canadian citizen (yikes!) or no Byrned Superman. Tough call, but that's what the multiverse is for.
Imagine that DC Comics remained an independant company, or formed its own conglomerate. Instead of ending up a minor subsidiary of TimeWarner. The family that owned DC (into the 60s on our earth) makes some investments that pay off & make them billionaires.
Jack Liebowitz would have to die in that universe --maybe an angry Jerry Siegel could pull the trigger (or, in an echo of the myth of the death of Balder, the Donenfields could direct a blind Joe Shuster to do the deed).
Imagine that Continuity Comics was a commercial success. It had great characters, some pretty good stories, & Neal Adams. A blockbuster movie/tv series (or more than one) based on its characters would have provided Continuity the revenue it needed to thrive.
Neal Adams would have to be dead in this universe as well, in order for Continuity to thrive.