The SYSTEM (the US Republic) worked. The system is resilient by design and performed as expected to deliver the appropriate output on the input it was given.
There is no deus ex machina. This isn't a movie. People have to work to save democracy.
No it was not. Go watch that famous YouTube video about the keys to power.
They had nothing, no source of power at all. At the bare minimum they would have needed the military on their side. Or 20 million people. They had neither. (Yah - even with all the people voting for Trump, only a fraction of a fraction were willing to use violence. The overwhelming majority were unhappy, even very vocal, but they accepted the results.)
It was basically a riot. A bunch of idiots making a mess and destroying things. Even if they had "succeeded" they still would not have had any power.
Your description would make more sense if they had done it after Biden was president, but they didn't.
Edit: It's almost as if you have to let each side feel that they are correct that "the other side" is indeed worse, but also communicate to them that it doesn't matter in the big big picture, and pursuing any manifestation of that opinion is counterproductive.