You say a whole new level, but what do you actually mean in terms of specifics as you haven’t provided any.
It can’t possibly be intellect, people and social skills, judgement, speed of thought, good manners, ability to read a room, self-awareness, communication skills, diplomacy, critical thinking skills or empathy.
I suppose she was more decisive but that is militated against by her truly appalling decision making.
So what characteristics did Truss possess that are on a whole never level to Starmer in terms of being discernibly better?