The overall point to this piece seems to be that impeachment probably won't happen, but it is a good organizing tool and it has grassroots appeal. If Benjamin actually believes impeachment is a practical possibility, then it is a glaring omission to not even mention Pence and what happens next, after Trump is out of office.
The example she gives for impeachment being a good organizing tool illustrates that it was a waste of time and energy. The antiwar movement died an early death the moment Obama took ownership of (and expanded) the "Bush" wars in 2008. And, as Benjamin notes, the Democrats didn't pursue impeachment once they gained the House majority in 2006. Why would we expect them to pursue it this time? In fact, it seems like impeachment was then and is now just a bait-and-switch gimmick for getting Democrats elected.
What's the point of organizing around an issue with grassroots appeal if there's no chance of winning anything? The world doesn't have time for us to keep repeating the same mistakes.