Do we know why they didn't move forward with Article three (3)

[FBaggins]

4. Trump already proved...

... that no matter how ridiculous a constitutional theory is, you can still find a law professor somewhere who will make the argument.

This is merely another example.

There is nothing in the constitution that gives congress the claimed power. They can only use it to exercise their existing powers (e.g., either impeachment or refusing to seat a newly elected member)