> there's no plausible way the people there would have seized power.

Sure, there is. Make Pence incapable of presiding, convince (this may not be necessary if the person is already a sympathizer), by inducements or threats, the person acting as President of the Senate to act in the manner Trump and various political allies had encouraged Pence to and which Pence had refused and simply decline to present certain state electoral votes, denying an immediate majority and either requesting friendly state legislatures to send alternate ballots, or preceding to vote by states in each house in the absence of a majority.

The “they couldn't have seized power” argument only works when you consider the people physically inside the Capitol as a separate force completely unrelated to the people that set out the goals in writing, the people that—publicly and unambiguously—told the people to go to the Capitol to get Congress to follow the goals set out in writing, and the people in State legislatures and in Congress who had publicly backed the goals set out in writing.

Which is a bizarre level of willful blindness.