And so we have the True Guardians of Equestria:
Queen Table McDeskface, who knows all, sees all, and whose wisdom surpasses any pesky ‘alicorns’.
And the Element of Magic and Friendship, Starlight Glimmer, the single most powerful pony to have ever existed and will ever exist, proving once and for all that becoming a Princess makes one weaker, cursing them with slowly fading into obscurity and obsolence.
And so it is that the aforementioned ‘Princesses’ assume the role they were almost meant to play: To serve as scratching posts for new up-and-coming villains (or a hoofful of generic changelings) to trounce and feel better about themselves - and as general cushions. They are quite soft.