Unity with Republicans has always meant capitulation to their whims since Clinton gave us "triangulation". They call for unity and refuse to budge from their far right positions so Dems must move toward them or be accused of divisive tactics. Even their compromises move Dems to the right.
Trump has given Dems a chance to force things back to the left a bit, but the attention span of Americans isn't long, so they must come out of their corner swinging at the end of this month. Republicans will strut around to create the illusion of some power, but they have none at the moment. If Biden and the Dems in Congress can't get some big legislation passed quickly it is because they don't want to. The stature of a Republican in Congress at the moment is lower than it has ever been.