What are the main reasons people are voting for Biden?

I'd wager the majority of people voting for him are doing so because he's not Trump. I heard on a very good podcast (The Portal #41) recently a great analogy. I'll paraphrase because I don't remember it fully:

A lion and a hyena are fighting over an injured but still alive warthog. To ask the warthog which animal he would prefer to be eaten by would be absurd.