Largely thanks to the efforts of Bernie and his supporters, the superdelgates mostly are no more. They only come into play now if no candidate who survives to the convention can get to a certain percentage of votes. Don't recall what the figure was, but in the 2016 election for example there would have, under these rules, been NO superdelegates.

Of course with seemingly 463 Democratic candidates running it is possible, ironically, that the superdelegates could come back into play. Even then, if I recall correctly, there are fewer of them though.

Also, the Overton window has moved quite a bit; progressive policy is no longer seen as so extreme. The people want progressive policies and the centrists and corporate Dems are, for the moment, having to tamp themselves down and move left. So I do not see them as quite so strident and moving in lockstep. Though they are still a significant problem.