When Fallout 5 comes around, would you rather have different backgrounds with their own "main" quests, one linear backstory like Fallout 4 or 3, or a blank slate like New Vegas?

I think it depends on a lot. I'd personally like different backgrounds with their own questlines as long as they weren't terribly short, but I imagine they would be if they were going to have different main quests, even if they were basically the same thing in different flavors.