Trump was not a "rando private citizen." He was a former President, a celebrity and a billionaire. Trump was far, far more well known than Harris, and arguably more connected to political power.
VP is not a powerful position. It's well known for being almost entirely pointless, unless the President dies.
Teddy Roosevelt’s opponents within the Republican party orchestrated his selection as vice president specifically to get him out of the way because they didn’t like what he was doing as governor of New York and figured that was a safe place to dump him. Then President McKinley was assassinated a few months later.
VP is not a powerful position. It's well known for being almost entirely pointless, unless the President dies.