Right, the complete absence of anything resembling a council does that.
She reveres Starswirl the Bearded to such an extent that she doubts her own ability and judgement. After all, it was The Elements of Harmony, the product of Starswirl, that allowed her and Luna to defeat Discord. Ever since the beginning, fans have never been completely satisfied with the level of effort Celestia put into trying to reason with Nightmare Moon. This lead to the Tyrant Celestia headcanon. What I think actually happened was that because she believes in Starswirl the Bearded more than herself, she’d be quicker to adopt the sacrificial, defeatist attitude he showed against The Pony of Shadows and use The Elements of Harmony, rather than her own ability to reason with Luna. Remember that in The Crystal Empire, Celestia talked about the virtue of self-sacrifice. So then, without Luna or The Elements, Celestia no longer believes she can change anything.
Based on that, my interpretation of Celestia’s actions throughout the series is that she’s using Twilight and her friends to vicariously experiment with not relying on things related to Starswirl the Bearded. This would actually make confronting Daybreaker a major development for her character. Rather that abdicating responsibility to someone else, she is finally able to solve a problem herself.
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