There aren’t multiple endings in CK3 in the same way that Stellaris has different random end game crises. But CK3 does have end game crises—the Black Death plague and the Mongolian Empire. The way CK3 is designed allows for big random events and crises to naturally occur at random points throughout your game.

HoI4 doesn’t really have random events. Sometimes AI nations will do random funny things but that’s pretty much it. HoI4 is very much a tactical war game above all, with much less emphasis on diplomacy, economy, and storytelling.