Harris is fielding Biden's important phone calls with world leaders. Why this is going on is strictly a guess, but my guess is Biden would sound like he was senile, and they know they couldn't hide that from the world media.
When are they going to pull the switch? Only and imbecile ignored this during the election, and anyone that hasn't quite figured it out, will soon have their cartoons interrupted. A real media would never had let Biden get in office, but we don't have a real media, and the rest of the world laughs at our idiocy.