Right now, Republicans control the White House, Senate, House and SCOTUS.
There's very little Democrats can do if they won't get some Republicans to join them.
This is why we should be creating the pressure on our politicians (yes, especially if they are Republicans) we also have opportunity to give Democrats control of the House and Senate which would change dynamics (yes, SCOTUS and trump would still stand in the way, but at least Democrats could do anything).
Yes, you might be frustrated with Biden, that he tried to return to the status quo, and that perhaps would actually work if Americans didn't vote trump back in, but it happened. Now it is very clear we can't return to the status quo and change is inevitable. We either create improved and better America (which happened in the past) or let it slip into authoritarianism.
Also DNC isn't one coherent party it is made up of smaller ones, it's basically party for everyone who doesn't support today's Republican party. There are caucuses like for example Blue Dogs which essentially are Republicans who don't like trump. There's also Promise to America (let's just compromise with Republicans) and so called New Democrats which are described as center left, but everywhere else they would be right leaning.
So Democrats have to negotiate with themselves whatever they want to do. If you are unhappy help vote then out.
For example, here is a spreadsheet that helps to track their performance:
I'm glad to see it is getting more and more progressive, but we need more.