One of the main problems with democracy is that it incentives politicians to buy voters, rather than use principled judgment. Everything becomes "politicking" to the lowest common denominator, because they have the most votes, and are most influenced by emotion.
Every system has it's flaws, and ultimately, I believe the problem is the people, not the government. If people were more principled, they wouldn't be susceptible to this emotional rhetoric. Monarchies are not inherently unjust, although many of them have been.
One additional problem with democracy, at least in the US, is that it sells out to the highest bidder. The masses are easily manipulated with TV and other propaganda, and they are the ones who elect the winner. It's like an oligarchy - the politicans are beholden to big money.
But people blame the politicans, not the oligarchs. They vote out "bad" politicians, only for new puppets to take their place, protecting the true masters (business interests, wall street, etc).
In a true oligarchy, people eventually go for blood. It's a joke to think that the riots on Jan 6th would do anything - kill the puppets, and the puppeteer brings in a new prop.
If you find this topic interesting I highly recommend Plato's Republic available free: https://www.gutenberg.org/ebooks/1497