"The Event" isn't the whole of it though, Trump tried a lot of different ways to try to get the result overturned. The events of Jan 6th are only a small part of the picture.

They may not have been a believable threat. But trying to strong-arm more votes out of various places, refusal to concede, throwing around unfounded allegations of mass cheating, constantly, and then the mountain of lawsuits and talking heads... it's beyond the pale.

If they don't see that threat, when would they? Because from here it looks far more like they don't care so long as it's their guy. And that's scary.

Different people will have different thresholds, through I would suspect that people will start to react if the military started to take political sides. I can only speculate, but I think a lot of people tune out when most of the events occur on twitter or in political speeches. I think also that people got a bit desensitized to mountains of lawsuits occurring from the whole period between 2016 and forward (a trend that might have started even earlier). The details are different but if people are toned out then they won't be listening to hear the details.

It is generally hard to make people care about a threat that they don't perceive, and even more if they view the whole process as being done by fools and jesters. The many Capitol Building riots memes is a good example where people are mostly joking about how incompetent the people involved was, rather than portraying a realistic and scary threat.

It is hard to have a more polarization response than one side laughing because they see fools and the other being scared because they see a realistic threat.

Right, but you're still focusing on the capitol building. If that's all that people perceived to have happened then they really weren't paying much attention.