If Biden had gone, he would have certainly made a fool of himself and the United States in many ways. But with American credibility already at zero due to Biden and his 'woke' clown-car staff, he would not have made things worse than they already are.
Enter Kamala Harris. She is so abysmally poor at 'speaking' in general. Whether to a group of child actors or to a fawning slobbering so called journalist who only wants to make her look fantastic, no matter what she fails every time and drags the interview into a laughing stock absurdity.
Whereas Biden is comfortable and even looks comfortable with constant failure, he is good at riding the zero line of credibility. However Kamala, unlike Sleepy Joe has the ability to take American gravitas and credibility well below the zero line. She will be seen by the world as a laughing incompetent 'joke' and of course, that is how the world will see America as well.
Understand that in most other countries the people in positions of power, other than sheer nepotism, are ruthless master politicians who are smart and keen as a dagger. They got to that level by dodging knives and traps their entire career. When the world sees a doddering old man and a stupid incompetent giggling teenager leading America, our enemies are emboldened and cheer, while our would-be allies are embarrassed and quake with fear.