The CARES Act was a compromise, the refusal by the House to enforce subpoenas was a compromise. Even their choice of presidential candidate is a compromise of sorts, see Biden's "nothing would fundamentally change" comment to donors. Where do you see obstructionism on their part?

A number of places, but just for example: Sanctuary cities. Even though they lost the battle on the federal level, the cities try their best to obstruct the enforcement of federal law.

In the political context obstructionism refers to attempts to delay or otherwise interfere with the legislative process. Which the Democrats may engage in, but I haven't seen any evidence demonstrating that.

Sanctuary cities do not obstruct the legislative process, they are just a form civil disobedience. This probably can be deemed obstruction of justice, but that has nothing to do with obstructionism.