He was not legally elected therefore he does not have to be impeached. Just hauled out of that office and locked up for having the greatest fraud machine ever. By his own admission.

Here's my take on this.

1. For sure investigate it. There's something fishy going on. I would actually investigate whether or not Biden or people in his administration got money for the military hardware they left behind for the Taliban. It seems to me like this whole thing was a weapons deal with collateral.
2. A retreat is not illegal. Our military leaders have certainly retreated in the past. When that happen most of them get replaced. How do you think Ulysses S Grant got promoted to be a Union general? His predecessor couldn't pass muster. It is certainly a showcase of bad leadership BUT it's not a crime to withdraw troops. Impeachment is for crimes committed while in office. Everyone is so quick to impeach when they don't really know what it's for.
3. If over the course of the investigation there is proof and evidence that Biden intentionally botched the pullout job for personal gain then that IS A CRIME and he can and should be impeached. If we get evidence that he facilitated the sale of the weapons and ended up with money at the expense of our fellow Americans then it should be real easy to lock his ass up. At that point he is a murderer of his own people.

Symbolic theater, though.