The sitting president directly used its office, power, platform to try to stop a democratic process, and launch/command an attack against a different branch of the government (the legislature). Even if that attack was purely symbolic. (... though calling it symbolic while people died is not entirely right.)
A radicalized subgroup of the fanaticized Trump cult used force to thwart a democratic process they deemed fake/undemocratic. And they managed to successfully pause that process for considerable amount of time.
Especially the stark contrast between the interaction of police and Trump cultists compared to police and BLM protesters points to an other serious problem.
...
That powerless group of people includes the sitting president, a bunch of senators and representatives, and they had a very very real chance of winning the election.
That same powerless group, at least a part of it that choose to do so, managed to basically stroll into the Capitol, loot it, and go away unharmed. (They got tear gassed eventually.) And this group included an elected state representative, various police officers, veterans, lawyers, and other not exactly powerless members of society.
This is about status, which is about perception. Conservative ideology is about social order, the status quo. This 'powerless group' wants to maintain their power, despite the results of the democratic process - which is designed to measure exactly that peacefully.
This is very much a thing. It's a serious ongoing thing. It has been ongoing forever though. And it's going to go on for ... well, probably forever too, but that only means other will have to expend energy to actively push that status quo toward a more fair equilibrium (or set-point).
politicians, however, are in such a position, though even that is a relatively remote possibility. luckily trump had no chance of retaining the presidency, by force or otherwise, mostly because he's too self-absorbed, and frankly stupid, to effectively consolidate power like xi jinping or putin did.