Sorry to be the voice of dissent again but why on earth wouldn’t she? Biden as the nominee is the reality now, it’s literally him or Trump.
With Biden’s health and faculties in question, it’s probably more likely than ever that his VP will end up as acting President at some point in the next 4 years. If she gets the job, she’s in a much, much better position to push through her agenda.
Honestly I’m starting to think there’s a large section of the left that are actively only happy when they and their preferred candidates are ineffectually carping from the sidelines