So far as can be determined, the January 6th rally was perfectly legitimate, and the actual storming of the Capitol was related to the rally only by the timing of it.
The actual assault was prepared in a completely different venue, under a false flag, as a means to intimidate the members of Congress into a panic vote, to close off ALL challenges to the vote totals presented for each state’s electors, and let the rather lopsided results stand.
The vote count was neither legitimate nor supported by objective observations.
Once you get them riled up, it is EASY to stampede the buffalo herd off a cliff. Just takes a little steering to guide them on the path to destruction.
Your reasoning is sound. The biggest loser because of the incursion into the Capitol was President Trump. The opportunity to have actual evidence of election fraud written into the Congressional Record was lost forever. It would probably not have changed the outcome of the election, but at least the left would not be able to say forever that “there was no evidence.”
Subsequently PDJT and his supporters are being “canceled”, denied job opportunities, refused book contracts, accused of crimes, etc. There is no way that President Trump would have incited a riot anywhere, much less at the Capitol.