He’d thought about this often. The Undying Sun Sect was not that powerful in the grand scheme of things. Shuchang and Hou Jingshu were stronger than their strongest members. They could have easily demolished them if they wanted. The reason they weren’t was simple.
Mei Xilan wanted the people to win back their freedom.
He understood her goals. By enabling the people to reclaim their freedom themselves, Mei Xilan was ensuring that her rule, once reinstated, was seen as legitimate and supported by the populace. A victory handed to them by external power might not earn the same level of respect or loyalty, especially since none of them planned to remain in the Sui Kingdom after the Undying Sun Sect was ousted. If they gave the kingdom to her and then left, her rule would become unstable since she had not won anything under her own power.