Part 1: Why Phantoms are shite
If vanilla minecraft was perfect we wouldn't be running paperspigot and dozens of plugins. In my view an extension of the "vanilla with sprinkles" slogan is that we don't make gameplay modifications without good reason, but we do modify vanilla game play quite substantially when it makes sense. Portal restrictions, world size, creeper/enderman/villager/golem behaviour are all non-vanilla and all have a big impact on gameplay.
Mojang have a rich history of