Princess Twilight "Twiggly-wiggle" Sparkle makes a much better ruler of Equestria than Celestia ever did. Why? Because one, she's Twilight Sparkle. Two, she's Twilight Sparkle. And three, she's Twilight Sparkle. Twilight Sparkle is the best Twilight Sparkle. Twilight Twilight Twilight, Sparkle Sparkle Sparkle, Twilight Twilight Sparkle Sparkle. Have I mentioned how much I absolutely adore Twilight Sparkle and think she's literally the best pony in existence?
Obviously I'm very biased towards Twilight, so since she's the ruler of Equestria now I'm gonna have to say that Twilight is the better ruler. Sorry @DivineKnight1000 I know how much you love Celestia, but I'm afraid that Twilight has Celestia beaten here
Also this-
What more reason do I even need to confirm that Twilight is the better leader?