1. Biden was never in it. The early national polls that showed him in the lead were rigged to make the impeachment narrative stronger.
2. The dems knew all along that impeachment would fail in the senate. The intent was to make the senate republicans look corrupt, hoping to put the senate in play for the dems.
3. If the senate flips to dem they can stop Trump's judges.
An interesting theory but it doesn’t explain the pelosi staged temper tantrum...