The problem for Warren’s media fan club is that “better than Bernie” is a low bar. Warren’s supporters can dismiss claims she is not particularly likable as sexist, but it is untrue (see: the latest coverage of Ted Cruz). The media’s power to convince people that someone is likable is limited.
Similarly, Warren seems to lack the sort of authenticity seen in Biden and Sanders (or in Trump and Alexandria Ocasio-Cortez, for that matter). The “Fauxcohontas” scandal may not be fatal in itself, but it feeds the impression that Warren—whom many forget was once a Republican—is never quite what she claims to be.
Some may dismiss likability and authenticity as intangibles or matters of style. Sadly, American politics has devolved to the point where voters treat the presidency is a personal relationship. Given the degree to which President Trump has dominated an ever-accelerating news cycle, voters may be even more attuned to the personality of the person who will be on their screens for the next four years.
Meanwhile, a battle between Warren and Sanders benefits Biden.