It's not about the numbering.
You'll be hearing a lot this week about the publishing milestone DC Comics' Action Comics has achieved, with the publication of issue #1000, on shelves (physical and digital) today. And I don't mean to dismiss that achievement, believe me. It's 2018, and periodical publishing is a lot like the Man of Steel in the penultimate panel of 1992's "Death of Superman" storyline: Beaten to a bloody pulp and hovering at death's door.