Typically how this goes is that a centrist liberal Democrat will get the nomination, and then push the left and progressives to support them because this centrist liberal can be transacted with. Once in office, they'll stomp all over the left and progressives, do literally less than the bare minimum needed to support the idea that they are in fact trying to get support from progressives and leftists, and then demand more votes four years later so progressives and the left can all get taken for another ride by some rich asshole who has more in common with Elon Musk than they do with most Americans.
Clinton more or less promised this type of governance to the left, and only tried, all too tardily, to come around after it became clear that people might actually not show up for someone who openly hates them and literally does not share their politics, and that raw identity politics alone was not going to be enough to get her into government.
Biden, surprisingly, has out of nowhere done a variety of progressive things. He allowed himself to be pushed on student loans. Like actually though. He banned non-competes, which won't fix capitalism, but if you're a capitalist liberal who believes in transacting with the left and in properly managing markets through policy, then that was a 100% necessary move. And he did it, without even that much fanfare.
While he'll never be pro-labor in the way I would want to see in order to be a supporter, the fact that he is actually willing to engage in transactional politics with progressives/the left really does count for something to me. He's still a strikebreaker and I won't give him credit for being a pro-labor candidate, but being willing to cut deals on things here and there does mean he has something to offer.