u/Proud-Tooth-630

TLDR at the end Celestia = Tytos, Twilight = Tywin

The sheer incompetence and recklessness of this would be princess is palpable, and her reliance on her subordinates to handle the turbulent matters of state reveals an incredible weakness in leadership. Her failure to fully deal with and defeat her sister Luna once and for all, led to her return to equestria from the moon to wreak havoc on the realm. The full range of implications needs to be understood here, the absence of the sun would mean the destruction of all the crops and a failure to sustain any life in equestria. This is an extinction level which would directly result in the death of millions of ponies and animal life. The terror that Luna wrought over Celestia's subjects was fully avoidable if she just did her job, the only excuse you could possibly scrape is that this was an event of professional development for the Mane 6, but tell me what sane leader would rely on the hopes and prayers that their subordinates would be able to handle it. In addition, this getting out to the public would be an absolute scandal; to be a citizen pony of equestria and know that your princess, allowed such terror even if brief to be inflicted on you for the reason of "training the mane 6" would immediately break my faith in her. This is equal to when Cersei blew up the great sept of baelor, this event would unquestionably have led to rebellion, and it would entirely be Celestia's fault.

The Changling invasion: When Celestia confronts Queen Chrysalis and gets bodied, her response effectively collapses until the Elements and Cadance's power turn the situation around. This is your queen???? This is the pony entrusted to keep the citizens of equestria safe???? You fight a single time, lose then roll over and die? Given that Celestia has centuries of experience and possesses extraordinary magical power, her inability to prevent the invasion is one thing; to be fair Chrystallis fed a lot of Love off shining armour and if theres no limit to her absorbtion then I guess I can understand but her apparent lack of a contingency plan for an enemy capable of infiltrating the royal capital is another, or even stepping up as a leader and fulfilling your duties til your death. Celestia isn't just some pegasus, the lives of literal millions of ponies are in her hands, and these failures need to be checked.

I could go on but I don't wanna write too much so I'll just add in one more tiny piece. Starlight Glimmer is the Mountain Gregor Clegane. She is the mad dog of Equestria and her blatant violation of magical principles, and the fact that she is capable of time manipulation and brought an ENTIRE town under her control should be grounds for execution. Starlight is far too much of a risk and broken cannon to be left to her own devices, yet she is still being protected and kept alive by celestia and twilight. Now who does this sound like....

And this really just is the utter failure that is Celestia: she is Tytos Lannister with a cutie mark. The rebellion of the Tarbecks and Reynes and the constant laughter and disrespect of House Lannister is exactly what Celestia has allowed in her own lands. They are laughing and calling her weak, and their all so painfully correct. Lady of the kingdom and protector of the realm, all the power in the world at her hands and none of the spine to use it when it actually matters. This washed princess lets Luna become Nightmare Moon, lets Chrysalis invade the realm and generally allows extinction level magical threats to repeatedly return, and then acts as though throwing Twilight and her friends at the problem is a solution. Tytos's great failure was believing that being a good man was enough to make him a good lord; Celestia makes the same mistake on a vastly greater scale, at the scale of Baelor the Blessed. If Celestia was queen in westeros the ironborn would own the seas, The North would still have a king, kingslanding would genuinely be getting sacked every other year and dear god forbid the rings that would run around her if Olenna or Tywin secured a royal marriage. I genuinely think her plan for dealing with the white walkers would be trying to talk the night king out of it. Someone who holds millions of ponies in her hands cannot afford to treat existential threats as exercises in character development. You don't gamble the crown and call it mentorship. Twilight becomes Tywin by necessity: the heir to the throne (lets be honest, NO ONE else is fit for the crown than her, and I don't even like twilight) who looks at Celestia's weak handed rule, the shame she brings upon the House of The Pegasus, sees the disasters it has enabled, and in anger but still love for her mentor/parent that discipline needs to be handed down to the realm. The only way for peace to be established is if the Honor of the house is restored, people respect the rule of the crown, and rebellion is violently put down at its inception. Too many beings do not fear the wrath of the crown, so many are just so comfortable raising an army and attempting to crush the Princess's peace. When the time comes and Twilight ascends the throne, she must establish one thing, she is not Celestia. Twilight needs her own Rains of Castamere.

TLDR: Celestia = Tytos, Twilight = Tywin. Starlight Glimmer is the Mountain in MLP and Twilight needs her own Rains of Castamere to establish discipline and peace in the realm.