This is in fact true. If people voted for Democrats overwhelmingly and then primaried the DINOS like fetterman and the corporate shills like Newsom and Shumer we would see the change we want eventually. FDR did it. He did it with supermajorities in both houses of Congress and he also needed 4 terms to remake the supreme court.
It's a generational project, and supremely unlikely to happen because a significant part of the electorate does not want it. But it could happen. If voters shifted 30 points to the left and stayed there for a generation it would happen.
Yeah this is not an explosion, it's a simmer.