Manchin and Cinema are Dem in name only, their actions are GOP at every turn.
Don't forget, 3 of the 5 SCOTUS were appointed by Trump, so everything happening with them now is from that and Biden doesn't have power to stop that.
And either way, both Dem and GOP are Right Wing parties and their goals are more or less to maintain the status quo, benefit corporations and elites, keep power, etc.
Neither party has interests or incentives to truly progress things that benefit people, except in maybe a scrap or two to get votes.
We don't really have a government by the people and FOR the people right now. If we did we would have Ranked Choice Voting, no more Electoral College BS, no more Gerrymandering, Voting Day would be a federal holiday, mail in ballots would be universal and accepted, etc etc etc.