I have no doubt misogyny plays a role with any woman in politics (or any other field, for that matter), but close to 66 million Americans *did* vote for Hillary Clinton in the 2016 General Election. And that was after she beat out Sanders in 34 of 57 contests and 16,914,722 vs. 13,206,428 cumulative votes in the primaries. Americans *will* vote for a woman.
The bigger problem for Warren in 2020 is she went to the left and found Bernie Sanders already encamped there with his millions of pre-existing supporters carrying over from 2016. There is only one slot for the eventual nominee and she simply got crowded out primarily by the positioning choices she made.