I'm not even a full on Biden supporter, but I hear his detractors say that garbage.
Please explain to me how a senator from Delaware is supposed to "change the country"? That is literally impossible. The same can easily be said about Trump, he's had 4 years in office, 2 years holding both the Senate and House, what fundamental policy agenda has he really accomplished?
It's such a strawman argument to say that, it holds no substance. When Obama was voted in the conservative argument was "He's too junior!", "He's barely been a senator!", now the argument against Biden is "He's been in government for so long!".
Which one is it?
As stats, nothing is assured given all the voter suppression tactics the Republicans have been playing with in this election. But given the record breaking early voter count (66 million), that news plays positive for Biden.
The more people that vote, the worse it is for Trump and the Republicans, which when you say that out loud, is quite illuminating, and saddening that we've become used to this idea of "minority governance".