It's also just the analytics, and the urgency/randomness of this playoff format. Closers don't often get the clinching save in a World Series anymore either.
In the Braves case they should definitely have more starters but one of them is Ian Anderson (demoted) and of course they lost Folty in recent years. And they are just straight-up using starters as relievers, as we really are too, and as the Rays, Dodgers and Astros have for years.