Your mistake is thinking that they wanted to stop it.

There was never any actual coup attempt or chance of overthrowing the government. It was a bunch of idiots thinking storming a building would be a good “yeah we’ll show them!”. There was no plan on how exactly they were going to overturn the election, no plan to hold all the government hostage and form their own government.

The fbi loved it because they can use it as more ammo to extend their powers and exert their existing powers on people to scare them into submission.