I'm sure I'll be banned shortly, but sure I'll give you an answer.
First, populations grow. A larger population, and also a more polarized and invested population voting can account for more votes.
I didn't vote for Biden because I liked him, or like him more than Obama. A large driving factor for me and a lot I know is simply wanting Trump gone. One thing I think a lot of people here fail to acknowledge whether they think it's justified or not is that Trump is polarizing. Many absolutely hate him, and that is a driving factor to get out and vote.
I doubt this will satisfy anyone, but hey, I've tried.
I'll start by saying I didn't come here to try to argue, I'll give my perspective and keep it short. I know we aren't going to agree.
I don't think Hunter is of any importance. I think the stories about him range from complete lies to blown out of proportion, but more than that Hunter isn't Joe, and there's no sign that he'll have anything to do with anything.
I think what Trump has done bringing Ivanka and Jared and having them so public facing and doing official work for his administration is rather unusual, and there's no reason to expect Hunter to be at all involved with Biden's administration.