There's no nice way to say this, but you watch too much TV. If you want to know how coup d'etat actually works Luttwak wrote a nice handbook[1]. Needless to say none of those conditions held on January 6th 2021.
There's no nice way to say this, but the implied definition of a coup from the reference you gave (i.e. generals take over the capitol) is only a very specific form of a coup, and to suggest that political manoeuvring and populist tactics don't form the basis of a coup, is completely wrong.
Mussolini's coup, 'March On Rome' [1] is a good reference, but there are plenty of historical examples.
Needless to say, the conditions on Jan 6. parallel key elements many historical coups.
" The highest-ranking U.S. officer, Chairman of the Joint Chiefs of Staff Gen. Mark Milley, and other top military leaders made informal plans to stop a coup by former President Donald Trump and his allies in the run-up to the 2020 presidential election," [2]
(there are many sources for this).
So first, you're at odds with the Chairman of the Joint Chiefs of Staff, who likely has an inkling of what was a 'coup' is.
Fabricating a constitutional crisis and fomenting mass populist furor is definitely a path to a coup, which he was obviously pursuing.
The reason that the VP et. al. reconvened immediately after the Jan 6 riots, directly in the 'still dangerous' aftermath - was because they wanted to make sure that the proceedings were as legitimate as possible, with little deviation from historic and traditional norms thereby minimizing the ability of the former President to create false narrative about it, and reducing his ability to sneak procedural and legal barbs into the process, which is defined by some really vague old laws and is established by tradition and precedent as much as anything.
Here are some good historical references, they make for good comparisons [3][4].
I think the chances of him fully taking over were small, but the chances of him mangling up processes and creating a kind of an oddball legal situation which would take many months to resolve while his supporters increased their level of agitation (we saw millions in the streets for BLM, no reason to believe his supporters mightn't have done the same) as a very real possibility.
[1] https://www.hup.harvard.edu/catalog.php?isbn=9780674737266