Trump was on the ballot, and all but a few of his big endorsements flopped hard. He is the GOP's gift to the Dems that just keeps on giving.
The majority of Americans are sick and tired of MAGA extremists who brag about how they want to screw over everyone else in the name of their own freedom and cry victim anytime someone else's freedom gets in the way. The majority of Americans do not support the MAGA mentality of conspiracy theories and bigotries and burning down our institutions instead of compromising with our fellow Americans.
Without Trump and the MAGAs, without the nihilistic alt-right trolls, the Q Karen bible-thumpers, and the racist gun-toting uncles whose only solution to crime is police brutality, the Dems would have been absolutely crushed this year.
That the GOP and the conservatives are unlikely to learn from this lesson should be good news for the Dems.