Regarding the current Biden/Trump situation, I would bet on Trump because the chances for either of them winning are closer to 50/50, while the outcome odds for Trump are above 2.0 everywhere.
50/50? Why do you think that?
The first election was very tight and he disappointed many of his voters during its mandate.
Gotta side with @Saint-loup here, latest polls from
FiveThirtyEight are pointing to a Biden Win @+8.5. Majority of the swing states are in Blue right now.
Last time also, Fivethirtyeight had given 90% chance for Hillary and less than 10% for Trump. And everyone knows what happened in the end. We can't really trust the polls, because they can't accurately predict the difference in turnout for both the camps. Back in 2016, none of the polls could predict that the turnout among the Democrat voting block (especially with the minority voters) would be 6-7% lower when compared to 2012.