Trump has some supporters who are all-in MAGA types excited for his candidacy.

He has some voters who don't particularly like him but want to vote against Biden. The type that will just hold their nose while pulling the lever, rather than cutting it off to spite their face.

Biden only has voters who want to vote against Trump, and essentially zero voters that actually want to vote for him.

The "it's important to vote against Trump no matter who his opposition is" sentiment has died down some. Trump was already in office and their bigger fears never materialized. He didn't turn out to be Hitler, it didn't destroy the country and it wasn't the most important election of our lifetimes. The Russia thing ended up being a hoax, he acted less fascistically than Biden, all that. Leave aside what you think about his actual presidency or whatever. In hindsight the rampant hyperbolic expectations just seem completely unhinged and all the people making them unserious after the country saw the actual results of a Trump presidency. Maddow became the new Alex Jones and Keith lost his damn mind. Warning against how dangerous a second term is sounds not just hollow, but in boy who cried wolf territory.

The Democrats can't win with a candidate whose only appeal is not being the other guy when we already saw a Trump presidency... while not great... was fine enough by the standards of modern presidents in everything but tone. There's arguments for better or worse than average, but it surprisingly wasn't exactly outside of the normal parameters. There are people who could never support Trump who are still gonna just sit this one out if Biden is who's asking them to vote.