For one, the majority of people at the Capitol protests were unarmed so wouldn't have been able to bring about the author's fantasy of a knockoff day of the rope.
For two, the majority of people at the Capitol protests didn't intend to kill US politicians - which we can see by the fact that they didn't. If the majority of people there wanted to hang AOC, or shoot Mike Pence, or whatever, they would have tried to charge the Senate and House chambers from the second they broke in instead of walking around the Capitol aimlessly before breaking to the Senate and stealing a podium there.
For three, the protesters wouldn't have killed the few members of Congress (Hawley, MTG, Boebert) that were unabashedly pro-Trump and that Trump himself had defended. If you want to build up a strawman of everyone at the protests being a Trump loyalist that would have killed for the God-Emperor, then don't ignore that strawman when you want to dispose of politicians you personally dislike.
For four, there is no way Trump wouldn't have condemned the protests the second they stopped being protests and started being "fiery but mostly peaceful protests". He told the people there to go home the second they trespassed on Capitol property and started rioting. Trump was not, and is not, stupid enough to think that he could pull off a coup without the support of the military, and everyone, from Q boomers who sperg about the deep state, to liberals who pray a deep state exists and crushes everyone who ever stood against Hillary Clinton, Our Lady of Bluelandia, admits that he didn't have that. The one in-depth analysis of the question "Could Trump pull off a coup?" I read, which was done by a coalition made up of the AFL-CIO, the Democratic Socialists of America, the Sunrise Movement and a couple of other progressive groups - so wasn't going to be friendly to Trump - said very clearly that Trump wouldn't get any support from the military or the civil service. Trump would never have tried anything without guarantees of support from them.
For five, the whole thing just reads like a liberal's wet dream instead of a serious attempt at alternate history. I mean, it has a Congresscritter killing six people with pens, despite the fact he's blind in one eye. There is no way this can, or should, be treated as anything other than the Biden-supporting wine aunt's version of The Turner Diaries, with only slightly more gratuitous violence.