We seem to go round in circles on these discussions around 'who else' or 'is this the best they have'.
The reality is that it takes name recognition and fundraising power to get in a good spot for the dems. Those things come with time. Look at the primary that Biden won first time. He beat a bunch of fellow old timers.
You also have to ask who would want the job other than a career politician or a narcissist.
Taylor Swift would clean up. She would probably be good at it as well. But why would she want to.